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SPECIAL 


ANATOMY 


HISTOLOGY. 


WILLIAM  E.  HORNER,  M.  D., 


PROFESSOR  OF  ANATOMY  IN  THE  UNIVERSITY  OF  PENNSYLVANIA — MEMBER  OF  THE  IMPERIAL 
MEDICO- CHIR  UR  GIGA  L ACADEMY  OF  ST.  PETERSBURG— OF  THE 
AMERICAN  PHILOSOPHICAL  SOCIETY,  &C. 


Multum  adhuc  restat  operis,  multumque  restabit,  nee  ulli  nato,  post  mille  sscula 
praecluditur  occasio  aliquid  adjieiendi. 


IN  TWO  VOLUMES. 

YOL.  II. 

SEVENTH  EDITION. 

WITH  NUMEROUS  ILLUSTRATIONS. 


PHILADELPHIA: 

LEA  & BLANCHARD. 


AND 


BY 


1846, 


Entered,  according  to  the  Act  of  Congress,  for  the  year  1846,  by  William 
E.  Horner,  in  the  Clerk’s  Office  for,  the  District  Court  of  the  Eastern  Dis- 
trict of  Pennsylvania. 


SPECIAL 


ANATOMY  AND  HISTOLOGY. 


BOOK  IV. 


PART  SI. 

GLANDS — AND  THE  ORGANS  OF  ASSIMILATION. 

CHAPTER  I. 

Prolegomena  on  the  Structure  of  Glauds. 

The  intimate  structure  of  glands  was  but  imperfectly  attended  to 
previously  to  the  celebrated  Malpighi,  who,  in  the  year  1665,  pre- 
sented to  the  world  his  work  entitled  Exercitationes  de  Structura 
Viscerum.  Till  his  time  the  most  minute  inquiry  had  gone  but  little 
beyond  the  point  of  observation,  that  glands  consisted,  as  an  ultimate 
arrangement  of  their  particles,  in  small  granular  bodies  called  Acini, 
from  their  being  clustered  like  grapes  or  berries,  growing  very  closely 
together  around  a common  stem  and  its  branches. 

The  simple  idea,  propounded  by  Malpighi,  is,  that  each  acinus 
being  a gland  of  itself,  consists  of  minute  spheroidal  sacs,  which  re- 
ceive the  secretion  from  the  blood  vessels.  Darwin  at  a much  later 
period  modified  this  idea  by  advancing  that  the  change  occurred  in 
the  spheroidal  sacs  themselves.  The  celebrated  Ruysch  having  im- 
proved much  the  art  of  injection,  was  enabled  to  show  in  his  prepara- 
tions, that  what  Malpighi  considered  as  sacs  or  follicles,  were  really 
formed  of  convoluted  blood  vessels.  He  hence  adopted  the  opinion, 
false  in  itself,  that  the  substance  proper  of  glands,  is  formed  wholly 
of  blood  vessels,  and  that  the  minute  branches  of  the  latter  terminate 

Vol.  II.— 2 


6 


ORGANS  OF  DIGESTION. 


by  direct  inosculation  with  the  ducts  of  the  glands.  As  another  step 
in  this  inquiry,  Mascagni  and  Cruikshank  showed  that  the  secreting 
canals  in  the  mammary  glands  commence  in  the  form  of  cells — and 
Professor  Weber  has  discovered  the  same  feature  to  exist  in  the 
structure  of  the  salivary  glands  of  birds  and  mammalia,  and  of  the 
pancreas  of  birds. 

The  existing  state  of  opinions  on  this  interesting  subject,  is  de- 
rived from  J.  Muller,  Professor  of  Anatomy,  Berlin,  who*  has  an- 
nounced as  the  result  of  his  inquiries  on  the  structure  of  the  secreting 
canals  in  all  kinds  of  secreting  glands,  that  such  canals  are  found 
every  where  to  form  an  independent  system  of  tubes.  “ That  whether 
they  be  convoluted,  as  in  the  kidney  and  testis,  or  ramified  in  an 
arborescent  form,  as  in  the  liver  and  salivary  glands — whether  they 
terminate  by  twig-like  cceca,  as  in  the  liver — or  in  grape-like  clus- 
ters of  cells,  as  in  the  salivary  glands,  pancreas  and  mammary  glands 
— their  only  connexion  with  the  blood  vessels  in  all  cases,  consists 
in  the  latter  ramifying  and  forming  a capillary  net-work  on  their 
walls  and  in  their  interstices:  and  that  the  finest  secreting  tubes, 
namely,  those  of  the  liver  and  kidneys,  are  always  several  times 
larger  in  diameter  than  the  minute  ramifications  of  the  arteries  and 
the  veins.” 

This  doctrine  is,  therefore,  a modified  resumption  of  the  more 
ancient  one  of  Malpighi,  and  claims  merely  for  the  entire  surface  of 
secreting  tubes  what  Malpighi  thought  to  belong  exclusively  to  their 
incipient  extremities.  The  leading  argument  in  its  favour  being, 
that  in  every  case  there  is  a minute  vascular  net-work  of  capillaries 
discernible  on  the  parietes  of  these  canals,  and  whose  capillaries  are 
much  smaller  than  the  secreting  tubes  themselves. f 

Glands  of  the  most  simple  shape  are  mere  recesses  or  pouches  in 
the  thickness  of  the  membrane  or  surface  to  which  they  belong. 
(. Folliculi .)  In  some  instances  they  are  very  superficial  and  their 
bottom  is  reached  through  a wide  orifice — in  other  instances  their 
mouths  are  somewhat  contracted  like  the  neck  of  a bottle — in  other 
cases  they  have  a long  and  tortuous  course  ( Tubuli ) as  the  tubuli 
seminiferi  of  the  testicle.  In  most  of  these  modifications  of  a tubular 
arrangement,  from  the  shortest  to  the  most  elongated,  the  walls  of 

* De  Gland.  Struct.  Penit.  Leips.  1830.  And  Phj'siol.  p.  485.  London, 
1840. 

j-  See  Capillaries.  ^ 


GLANDS. 


7 


the  tube  are  not  absolutely  uniform,  but  it  will  be  found  that  there 
are  either  partial  or  cellular  dilatations  of  it ; or  coecal-like  appenda- 
ges, in  great  numbers  discharging  into  it,  and  placed  in  varied  an- 
gular relations  to  the  principal  sinus  or  secreting  tube.  The  stem 
of  a thickly  clustering  bunch  of  grapes,  the  berries  being  removed, 
will  represent  sufficiently  well  the  mere  mechanism  of  this  arrange- 
ment. 

A form  of  secreting  canal  a little  more  complex  is  where  a large 
spheroidal  dilated  sinus  exists  with  tubules,  radiating  from  it  [Folliculi 
aggregati)  in  lines  more  or  less  regular;  the  sinus  itself  having  a 
large  patulous  orifice  connecting  it,  with  the  surface  upon  which  it 
discharges.  One  of  the  follicles  of  the  tonsil  glands  may  represent 
this  arrangement.  Also  the  glandular  linguales  on  the  root  of  the 
tongue,  which  seem  to  be  a mere  extension  of  the  lower  end  of  the 
tonsil  gland  in  the  form  of  an  expanded  flank,  and  are  not  unfre- 
quently,  directly  continuous  with  the  tonsil  gland.  Another  form 
of  this  composite  canalicular  arrangement  is  when  the  collection  of 
tubules  is  more  in  a line,  the  branches  diverging  more  slightly  from 
each  other  ( Folliculi  compositi ) and  each  of  those  branches  again 
diverging  into  other  branches,  and  so  on  successively  to  their  last 
twigs.  The  Meibomian  glands  and  the  vesiculse  seminales  are  in- 
stances of  the  linear  composite  follicle,  or  tube  having  but  one  set 
of  branches.  A lactiferous  duct  is  an  example  of  the  composite 
secreting  canal,  or  tube  with  a numerous  and  indefinite  succession 
of  finer  and  finer  branches,  and,  -which  end  finally  in  club-like  dila- 
tations. Some  of  these  secreting  canals  end  in  a divarication  of 
branches  resembling  the  flowering  ends  of  the  umbelliferous  plants. 

Some  of  the  glands  present  a species  of  regularity  in  the  order  of 
division  of  their  secretory  canals.  The  principal  trunk  of  the  latter 
gives  off  at  intervals  nearly  uniform  lateral  branches,  these  branches 
give  off  with  regularity  other  branches,  and  the  latter  again  observe 
the  same  disposition.  This  modification  is  preserved  to  a remarka- 
ble degree  in  the  pancreas,  and  is  also  visible  in  the  salivary  glands, 
the  lachrymal,  and  the  mammary.  In  cases  of  this  kind  the  lobu- 
lated  condition  is  very  clear,  the  lobules  being  rather  feebly  held  in 
connexion  with  the  contiguous  ones  by  loose  cellular  substance, 
allowdng  the  lobules  to  be  easily  separated  from  each  other  by 
drawing  at  them.  The  lobules  themselves  are  ultimately  divisible 
into  granules,  [glomeruli  or  acini)  which  under  the  application  of  the 
microscope  are  found  to  be  aggregated  cells,  surrounded  by  a fine 


s 


ORGANS  OF  DIGESTION. 


vascular  net-work  of  capillaries,  and  making  the  peripheral  end  of 
the  most  minute  secreting  canals.  The  trachea  with  its  division 
into  bronchia,  bronchioles,  final  air  tubules,  and  air  vesicles  at  the 
end  of  the  latter,  represents  on  a large  scale  the  division  which  is 
seen  in  glands  on  a small  one.  An  unsettled  question  is,  whether 
these  vesicular  terminations  are  in  all  cases  kept  distinct,  or  whether 
from  a defect  in  their  parietes  they  do  not  communicate  like  the  air 
vesicles  of  the  lungs,  and  have  in  that  way  a tubule  common  to 
several.  In  some  instances  the  ultimate  secretory  tubules  of  those 
ramified  ducts  are  arranged  like  cosca  around  the  branches  of  the 
latter. 

Another  form  of  the  ramified  secreting  tube  is  where  there  exists 
no  division  of  the  gland  into  lobules,  but  it  is  resolved  at  once  into 
acini.  These  acini  being  formed  upon  the  final  divisions  of  the 
secretory  tube,  which  rise  up  in  fasciculi,  giving  a brush  like  or 
penicillous  appearance.  The  liver  is  an  example  of  the  above,  it 
being  doubtful  whether  there  is  any  spheroidal  enlargement  at  the 
free  end  of  the  penicilli.* 

The  glands  with  successively  ramified  secreting  tubes  are  the 

Lachrymal  gland, 

Mammary  gland, 

Salivary  glands  as  Parotid,  Sublingual,  and  Submaxillary, 

Pancreas, 

Liver. 

The  glands  of  an  almost  pure  tubular  structure  and  indisposed  to 
ramify,  except  in  a very  limited  manner,  are  the 

Kidneys, 

Testicles. 

The  Meibomian  glands  and  the  Vesiculse  seminales  may  oe  con- 
sidered as  a tendency  to  the  same  structure,  but  in  a more  abbre- 
viated and  simple  condition;  by  some  they  are  considered  merely  as 
branched  follicles. 


* From  peniculus  a painter’s  pencil. 


GLANlDS. 


9 


The  summary  of  the  secretory  glandular  system  then  is,  for  it  to 
present  itself  in  the  simple  short  tubular  state  of  shallow  depressions, 
or  crypts  of  a mucous  membrane  as  in  the  urethra  and  bladder; — 
in  bottle-shape  cavities; — in  closed  lenticular  cavities,  as  Peyers’s 
Glands; — as  the  follicles  of  the  alimentary  canal  which  are  either 
single  or  branched; — and  as  thin  follicles  with  a glandular  matter 
or  parenchyma,  principally  vascular,  forming  a nidus  around  them, 
and  which  follicles  may  themselves  be  either  simple  or  branched  in 
some  degree. 

The  principal  object  of  a secreting  glandular  structure  would  seem 
to  be  a development  or  augmentation  of  surface  sufficient  to  the  pur- 
pose of  elaborating  the  quantity  of  the  specific  fluid  called  for  ; in 
other  words,  for  getting  area  for  the  requisite  ends,  like  the  display 
of  surface  in  the  interior  of  the  lungs  for  air  enough  by  respiration. 
The  glands  seem,  therefore,  as  said  by  some,  to  be  a sort  of  efflo- 
rescence from  the  surface,  or  cavity  upon  which  they  discharge ; 
being  formed  of  canals  with  closed  extremities  as  originally  asserted 
by  Malpighi. 

It  is  denied  by  Muller*  that  there  are  acini  in  any  glands  what- 
ever (the  testes  of  some  few  fishes  excepted)  existing,  as  commonly 
understood,  to  wit ; as  solid  granules  executing  secretion,  by  means 
of  their  glomeruli  of  blood  vessels  having  ducts  arising  from  them,  in 
an  unexplained  way.  On  the  contrary,  he  asserts,  that  acini  are 
merely  bundles  of  fine  tubes  formed  by  the  ends  of  secreting  canals,  or 
frequently  by  collections  of  the  vesicular  terminations  of  the  latter. 
The  term  acinus  in  its  qualified  sense  is  sufficiently  proper,  but 
it  should  be  remembered  that  in  receiving  it  according  to  its 
meaning,  which  is  a berry  or  grape,  the  skin  of  the  grape  and  its 
pedicle  are  alone  to  be  understood,  the  pulp  being  omitted. 

In  regard  to  the  connexion  with  the  blood  vesssels,  their  cavities 
are  as  stated  according  to  Muller;  not  to  be  considered  as  continu- 
ous with  the  cavities  of  the  secreting  tubes,  but  merely  ramified  on 
them  by  countless  capillaries,  the  arteries  simply  terminating  in  the 
veins  as  in  the  case  of  the  lungs,  or,  I may  say,  of  the  intestinal 
canal.  This  theory  is  however,  almost  too  exclusive  ; there  are 
most  probably  organized  porosities  in  the  capillary  system,  I am 
disposed  to  think,  in  the  venous  especially,  forming  a communica- 
tion between  the  vessels  and  the  canals  on  which  they  ramify ; it  is 


* Physiol,  p.  501. 
2* 


10 


ORGANS  OF  DIGESTION. 


rather  too  easy  to  pass  a minute  injection  from  the  capillary  system 
into  the  canal  upon  which  it  ramifies,  for  us  to  suppose  that  every 
such  case  is  one  of  rupture.  We  must,  also,  upon  the  ground  of 
personal  observation  to  the  contrary,  decline  the  opinion  of  Profes- 
sor Muller,  that  there  is  no  communication  between  the  secretory 
ducts  and  the  lymphatics. 

The  cause  of  the  massive  character  of  many  glands  and  of  their 
shape  may  now  be  understood.  The  shape  of  glands  must  depend 
measurably  upon  the  space  and  circumstances  in  which  they  are  ac- 
commodated; the  diversity  of  shape  in  the  three  salivary  glands  shows 
that  this  is  a point  of  merely  local  convenience,  and  is  subordinate. 
Their  size,  however,  is  upon  another  ground:  this  is  regulated  by 
the  amount  of  secretion  to  be  done,  and  by  the  necessity  of  this  se- 
cretion being  collected  at  one  or  more  points.  The  process  of  as- 
similation requires  the  bile  in  the  duodenum,  only,  and  that  in  large 
quantity ; hence  the  liver  is  both  a very  large  organ  and  all  its  secre- 
tion, is  concentrated  in  one  focus.  If  the  necessity  for  the  latter 
had  not  existed,  the  liver  like  the  muciparous  glands  might  have 
been  disposed  in  small  granules  all  along  the  alimentary  canal. 
This  hypothesis,  by  the  way,  will  show  how  the  liver  or  any  other 
gland  may  exist  in  the  form  of  insulated  acini  without  the  function 
being  altered ; and  also  show  the  reverse,  how  if  all  the  muciparous 
glands  were  collected  into  one  mass  for  the  purpose  of  having  a focal 
point  of  discharge;  that  this  arrangement  would  require  also  a single 
large  duct  made  by  the  successive  junction  of  branches,  just  as  in 
the  liver. 

As  the  vascular  capillaries  ramify  upon  the  parietes  of  the  secre- 
tory tubes,  so,  their  parent  branches  are  found  in  company  with  the 
larger  branches  of  the  latter.  The  development  of  the  tw’o  systems 
is  found  to  be  simultaneous.  The  tubes  are  first  of  all  planes,  then 
simple  canals  or  coeca,  then  primary  branched  canals  or  coeca,  then 
undergoing  an  indefinite  series  of  divisions.  At  first  these  canals 
are  loose  and  unconnected,  but  as  the  evolution  of  the  gland  ad- 
vances they  cohere  and  become  consolidated;  but  at  every  period 
of  development  and  of  perfection,  the  capillaries  form  a net-W'ork 
around  them  smaller  than  the  tubes  themselves. 

There  is  no  essential  correspondence  between  the  construction  of 
a gland  and  its  secretion.  Very  different  glands  have  similar  struc- 
ture, as  the  testes  and  the  kidneys,  and  similar  glands  have  a 
varied  secretion  in  different  animals.  The  liver  in  one  animal  is 


GLANDS. 


11 


simply  in  the  form  of  coeca,  in  another  of  tufts  of  cceca  ; in  others 
of  branches  of  cells  or  of  a spongy  tissue,  or  as  a branched  duct 
having  terminal  twigs  like  a feather.  The  testes  are  indefinitely 
varied ; the  kidneys  alone  maintain  a constant  character.  The  con- 
struction of  a gland  is  always  regulated  by  the  special  demand  upon 
it  by  the  condition  of  the  animal  in  question;  hence  the  salivary 
glands  are  exceedingly  simple  in  birds  and  serpents ; the  pancreas 
in  fish;  and  the.  liver  in  the  lower  animals.  Where  more  surface  is 
required,  then  new  processes  from  the  main  line  of  the  secreting 
tube  spring  up. 

Recent  microscopic  observations  have  ascertained  other  new  points 
in  glandular  structure.  Purkinje  remarked,  that  the  walls  of  all  se- 
creting cavities  or  canals  are  formed  by  nucleated  granules,  of  the 
diameter  of  ys.hav  of  aline,  making,  according  to  his  phraseology,  the 
glandular  Enchyma , product , or  fluid.  With  the  aid  of  Schwann  and 
Henle  this  arrangement  has  been  found  in  all  the  glands  and  over 
the  entire  mucous  surface,  constituting  in  fact  a cellular  nucleated 
epithelium,  which  is  now  thought  to  execute  the  specific  secretion  of 
all  glands. 

The  determinate  physiological  doctrine  of  the  day,  may  be  then 
summed  up,  in  the  general  declaration,  that,  whatever  be  the  secre- 
tion in  question,  it  is  elaborated  through  the  growth  and  nutrition  of 
cells  covering  the  free  surface  of  excretory  tubes,  and  their  branches 
to  their  very  end.  So  far  as  the  microscope  can  avail,  there  appears 
to  be  no  difference  between  the  structure  of  the  cells  of  one  secre- 
tion and  those  of  another.  Their  capacity  to  eliminate  from  the 
blood  the  specific  secretion,  is  one  of  those  abstruse  acts  of  the  sys- 
tem, depending  upon  an  original  endowment ; a dictum  in  other 
words,  of  that  creative  energy  which  spoke  all  things  into  existence, 
and  still  continues  to  retain  them  in  it.  In  a case  of  this  kind  we 
may  possibly  rest  contented  with  the  wisdom  of  a former  period. 
Omnino  autem  cum  JDeus  aliquid  facit , nulla  opus  est  ratione.  Quo- 
modo  nos  ex  nihilo fecit')* 

Biliary  matter  and  oil  are  easily  recognised  in  the  above  cells  of 
the  liver,  by  their  difference  of  colour,  and  by  their  refracting  powers: 
— milk  is  detected  in  a similar  manner  in  the  mammary  gland;  seba- 
ceous matter  in  the  follicles  of  the  skin,  and  so  on  of  other  glands. 

The  above  cells  having  reached  a state  of  maturity,  and  accom- 


* St.  Joannes  Chrysostome. 


12 


ORGANS  OF  DIGESTION. 


plished  a perfect  secretion  within  their  own  cavity  so  as  to  fill  it,  this 
secretion  is  discharged  by  their  dehiscence,  or  dissolution,  and  is 
then  conveyed  to  the  point  where  it  is  wanted.  The  generation  of 
secreting  cells,  thus  exhausted,  is  succeeded  by  another  generation, 
and  so  the  process  goes  on  during  the  life  of  the  individual.  It  is 
thought  that  in  some  glands  this  succession  is  diffused  over  the  whole 
free  surface  of  the  excretory  tubes,  but  in  others  that  it  is  confined  to 
the  extreme  end  or  terminus.* 

There  are  some  other  organs  called  glands,  but  they  differ  from 
the  preceding  in  having  no  excretory  ducts.  They  are  supposed 
to  be  limited  in  their  function  to  the  modifying  in  some  measure,  the 
fluids  going  through  them.  One  kind  of  them  is  formed  essentially 
of  blood  vessels,  and  they  are  called  Ganglia  sanguineo-vasculosa ; 
of  these  we  have  the  spleen  for  the  chylopoietic  system  ; the  cap- 
sulce  renales  for  the  kidneys  ; the  thymus  and  thyroid  gland  for  the 
organs  of  respiration,  and  the  placenta  for  fcetal  life.  The  second 
kind,  called  lymphatic  glands,  (Ganglia  lymp/iatico-vasculosa,)  con- 
sist essentially  of  lymphatic  vessels  entering  on  one  side  and  de- 
parting at  the  other,  after  having  divided  into  branches  and  cells  in 
the  thickness  of  the  gland.  There  are  also  other  glands  whose  cha- 
racter and  functions  are  still  more  doubtful,  they  being  found  in  con- 
tiguity with  the  encephalon,  as  the  Pituitary  gland,  the  Pineal,  and 
the  glands  of  Pacchioni. 

The  real  glands  on  the  contrary  not  only  modify  the  blood  which 
circulates  through  them,  but  give  rise  to  a new  fluid  as  a consequence 
of  the  transformation  of  the  blood ; and  this  new  fluid  is  discharged 
for  a specific  purpose  by  its  efferent  tubes  into  contiguous  canals  or 
places. 


CHAPTER  II. 

Of  the  Abdomen  Generally. 

The  cavity  of  the  abdomen  occupies  the  space  between  the  infe- 
rior surface  of  the  diaphragm  and  the  outlet  of  the  pelvis  ; a con- 


Goodsir,  see  Carpenter  Elem.  Physiol.,  p.  409.  Phila.  1846. 


OF  THE  ABDOMEN. 


13 


siderable  part  of  it  is,  therefore,  within  the  periphery  of  the  lower 
libs  above,  and  of  the  pelvis  below.  It  is  completely  separated 
from  the  cavity  of  the  thorax  by  the  diaphragm,  with  the  exception 
of  the  foramina  in  the  latter,  for  transmitting  the  aorta,  the  ascending 
cava,  and  the  oesophagus.  It  is  bounded,  below,  by  the  iliaci  interni, 
the  psose,  and  the  levatores  ani  muscles  ; on  the  front  and  sides  by 
the  five  pairs  of  muscles  called  abdominal ; and  behind  by  the  lesser 
muscle  of  the  diaphragm,  the  quadrati  lumborum,  the  lumbar  verte- 
brae, and  the  sacrum.  The  figure  of  this  cavity  is,  therefore,  too  ir- 
regular to  admit  of  a very  rigid  comparison  with  any  of  the  common 
objects  of  life ; but  a little  reflection,  on  the  course  of  its  parietes, 
will  make  it  perfectly  understood.  It  should  be  borne  in  mind, 
that  the  very  great  projection  of  the  lumbar  vertebrae  forms  for  it  a 
partial  vertical  septum  behind ; which,  in  thin  subjects,  is  almost 
in  contact  with  the  linea  alba  in  front,  and  may  be  easily  distin- 
guished through  the  parietes  of  the  abdomen,  when  the  intestines 
are  empty. 

The  abdominal  cavity  varies  only,  inconsiderably,  in  its  vertical 
diameter,  owing  to  the  resistance  of  the  diaphragm  above,  and  of 
the  pelvis  below ; neither  does  it  change  behind,  owing  to  the  resis- 
tance of  the  spine,  the  ribs,  and  the  muscles  there.  But  as  the  in- 
troduction of  food,  the  development  of  gaseous  substances  during 
digestion,  the  evolution  of  the  foetus,  and  many  other  conditions,  re- 
quire some  provision  for  its  undergoing  an  easy  augmentation  of 
volume  ; the  latter  occurs  principally  forwards  and  laterally,  by  the 
yielding  of  the  muscles  and  by  the  extension  of  their  aponeuroses. 

The  diaphragm  and  the  abdominal  muscles,  for  the  most  part, 
act  alternately ; as  the  former  descends  in  inspiration  the  latter 
relax  and  give  way  to  the  contents  of  the  abdomen  ; but  in  expira- 
tion, the  abdominal  muscles  contract,  and  the  diaphragm  is  pushed 
upwards  by  the  viscera.  In  attempts  at  the  expulsion  of  feces,  and 
in  parturition,  these  muscles  contracting,  aud  the  diaphragm  being 
fixed  all  at  the  same  moment,  the  cavity  of  the  abdomen  is  actually 
much  diminished. 

The  viscera  contained  in  the  cavity  of  the  abdomen  are  of  three 
kinds.  One  kind  is  engaged  in  digestion  and  assimilation  ; another 
in  the  secretion  and  excretion  of  urine  ; and  the  third  in  generation. 
As  these  viscera  are  numerous,  and  it  is  of  great  importance  to 
determine  wfith  precision  their  position  and  relative  situation,  ana- 
tomists are  agreed  to  divide  the  cavity  of  the  abdomen  into  several 
arbitrary  regions.  This  is  the  more  advantageous,  as  the  bony 


14 


ORGANS  OF  DIGESTION. 


prominences  bounding  the  abdomen  are  not  sufficiently  numerous 
and  distinct,  to  afford  those  obvious  points  of  relation  to  the  vis- 
cera which  are  furnished  in  other  sections  of  the  body.  To  obtain 
these  regions,*  consider  a line  or  plane  as  extending  across  the  ab- 
domen, about  two  inches  below  the  umbilicus,  from  the  superior 
part  of  the  crista  of  one  ilium,  as  it  appears  through  the  skin,  to 
the  corresponding  place  of  the  other  side.  Strike  on  each  side  a 
line  perpendicular  to  the  preceding,  by  commencing  at  the  lower 
end  of  the  anterior  inferior  spinous  process  of  the  ilium,  and  car- 
rying it  up  to  the  diaphragm.  Extend  a fourth  line  across  the  ab- 
domen parallel  with  the  first,  and  intersecting  the  last  two  where 
they  come  upon  the  cartilages  of  the  false  ribs.  It  is  evident  that 
these  four  lines  or  planes,  twro  horizontal  and  two  vertical,  will, 
with  the  assistance  of  the  parietes  of  the  abdomen,  furnish  nine  re- 
gions: three  above;  three  in  the  middle;  and  three  below.  The 
central  region,  above,  is  the  Epigastric  ; and  on  its  sides  are  the 
right  and  the  left  Hypochondriac.  The  central  region  in  the  mid- 
dle, surrounding  the  navel,  is  the  Umbilical ; and  on  its  sides  are 
the  right  and  the  left  Lumbar.  The  central  region  below,  is  the 
Hypogastric ; and  on  its  sides  are  the  right  and  the  left  Iliac. 
There  are  also  some  subordinate  divisions : for  example,  the  hollow 
in  the  epigastric  region,  around  the  ensiform  cartilage,  is  called 
the  pit  of  the  stomach,  or  Scrobiculus  Cordis ; and  for  an  inch  or 
two  around  the  symphysis  pubis,  is  the  region  of  the  pubes,  ( Regio 
Pubis.) 

Anatomists  differ  among  themselves  about  the  points  of  depar- 
ture and  the  position  of  the  lines,  or  rather  planes,  separating  the 
regions.  Some  fix  them  at  definite  distances  from  the  umbilicus, 
and  others  resort  to  the  points  of  the  skeleton.  The  umbilicus  is 
the  most  fallacious  mark,  because  its  elevation  varies  considera- 
bly, according  to  the  state  of  distention  of  the  abdomen,  it  being 
comparatively  higher  when  the  abdomen  is  tumid  than  when  it  is 
not.  Neither  does  it  answer  to  take  the  anterior  ends  of  the  last 
ribs  as  the  points  for  the  upper  horizontal  line  to  pass  through  ; as 
they,  sometimes,  are  almost  as  lowr  down  as  the  umbilicus  itself. 
The  superior  anterior  spinous  processes  are  also  objectionable  as  the 
points  of  departure  for  the  vertical  lines ; as  they  leave  too  much 
room  for  the  central  regions  of  the  abdomen,  and  too  little  for  the 
lateral : I have,  therefore,  after  some  hesitation,  thought  it  proper  to 


* Anat.  Atlas,  Fig-.  297. 


OF  THE  ABDOMEN. 


15 


substitute  the  anterior  inferior  spinous  processes  ; and,  especially,  as 
the  position  of  the  viscera,  according  to  almost  universal  descrip- 
tion, is  more  in  accordance  with  this  rule. 


General  Situation  of  the  Viscera  of  the  Abdomen.* 

When  the  abdomen  is  so  opened  as  to  leave  its  viscera  in  their 
natural  position,  they  will  be  found  as  follows  : — 

1.  The  Liver,  the  largest  gland  of  the  body,  is  in  the  right  up- 
per part  of  the  abdomen,  immediately  below  the  diaphragm.  It 
occupies  nearly  the  whole  of  the  right  hypochondriac  region ; the 
upper  half  of  the  epigastric  ; and  the  right  superior  part  of  the  left 
hypochondriac.  The  anterior  extremity  of  the  gall-bladder  pro- 
jects beyond  its  anterior  margin. 

2.  The  Spleen  is  situated  in  the  posterior  part  of  the  left  hypo- 
chondriac region. 

3.  The  Stomach,  in  a moderate  condition  of  distention,  occupies 
the  lower  half  of  the  epigastric  region,  and  the  right  inferior  portion 
of  the  left  hypochondriac. 

4.  The  Small  Intestine,  when  moderately  distended  by  flatus, 
occupies  the  umbilical  region,  the  hypogastric,  portions  of  the  iliac 
on  each  side,  and  also  the  upper  part  of  the  cavity  of  the  pelvis, 
when  the  viscera  of  the  latter  are  empty. 

5.  The  Large  Intestine  traverses  the  cavity  of  the  abdomen  in 
such  a manner  as  to  perform  almost  the  entire  circuit  of  it.  It  be- 
gins in  the  right  iliac  region  by  receiving  the  lower  extremity  of  the 
small  intestine ; it  then  ascends  through  the  right  lumbar  and  the 
right  hypochondriac,  passes  into  the  lower  part  of  the  epigastric,  or 
into  the  upper  of  the  umbilical,  according  to  the  state  of  distention 
of  the  stomach;  thence  it  gets  into  the  left  hypochondriac,  being 
fixed  higher  up  there  than  in  the  corresponding  region  of  the  other 
side ; afterwards  it  goes  down  into  the  left  lumbar  and  into  the  left 

* Anat.  Atlas,  Figs.  299,  300,  301,  302. 


16 


ORGANS  OF  DIGESTION. 


iliac,  where  it  makes  a large  long  loop,  called  its  sigmoid  flexure  ; 
thence  it  passes  into  the  pelvis,  in  front  of  the  leftsacro-iliac  junction 
and  inclining  afterwards  to  the  central  point  of  the  sacrum,  it  sub- 
sequently descends  in  front  of  the  sacrum,  and  coccyx  to  terminate 
in  the  orifice  called  anus. 

6.  The  Caul,  or  Omentum,  is  a membrane,  of  various  densities, 
in  different  individuals,  and  lies  in  front  of  the  intestines.  Some- 
times it  is  found  spread  over  the  latter  like  an  apron,  but  on  other 
occasions  is  drawn  up  into  the  umbilical  region,  forming  a ridge 
across  it.  It  is  attached  to  the  stomach  and  large  intestine. 

7.  The  Pancreas  lies  transversely  in  the  lower  back  part  of  the 
epigastric  region.  It  extends  from  the  left  hypochondriac  region  to 
the  right  side  of  the  spine,  and  is  placed  behind  the  stomach,  so  as 
to  be  covered  by  it. 

8.  The  Kidneys  and  the  Capsulse  Renales,  each  two  in  number, 
are  placed  in  the  posterior  part  of  the  lumbar  region  on  the  side  of 
the  spine. 

9.  The  Urinary  Bladder  and  the  Rectum,  in  the  male  occupy  the 
cavity  of  the  pelvis,  and  in  the  female  between  them  are  placed  the 
uterus,  the  ovaries,  and  the  vagina. 

As,  in  the  dissection  of  the  abdominal  viscera,  the  subject  is  com- 
monly placed  on  its  back,  so  the  preceding  description  is  made  out 
with  a strict  reference  to  that  position.  Some  modification  in  the 
shape  of  the  abdomen,  as  well  as  in  the  situation  of  its  contents, 
occurs  in  standing  upright.  The  front  of  the  abdomen  becomes  then 
more  protuberant,  the  lumbar  vertebrae  make  a greater  projection 
forwards.  The  pelvis  is  also  so  adjusted,  in  order  to  bring  the  ace- 
tabula  directly  in  the  line  of  support  to  the  spine,  that  the  convexity 
of  the  sacrum  presents  almost  upwards,  and  the  superior  strait  looks 
forwards  and  upwards  towards  the  navel,  so  that  much  of  the  weight 
of  the  viscera  is  thrown  upon  the  pubes.  In  this  attitude  most  of 
the  viscera  descend,  but  more  obviously  the  liver,  from  its  weight, 
size,  and  solidity.  Portal  has  verified  this  descent  by  comparing 
the  thrusts  of  poignards  into  the  liver  in  the  erect,  with  those  inflicted 
in  the  horizontal  position.  He  also  asserts  that  the  same  may  be 


ORGANS  OF  DIGESTION. 


17 


Ascertained  in  the  living  body  by  applying  the  fingers  under  the  false 
ribs}  and  then  directing  the  person  to  change  from  the  recumbent 
into  the  vertical  position.  The  spleen  affords  the  same  results  when 
it  is  slightly  enlarged,  and  the  descent  of  the  liver  and  spleen  will  of 
Course  ensure  that  of  the  stomach  and  intestines.  According  to 
Winslow,  the  pain  and  faintness  which  are  felt  after  a long  absti- 
nence, come  from  the  vacuity  of  the  stomach  and  intestines,  which 
thereby  withdraw  their  support  from  the  liver,  and  permit  it  to  drag 
upon  the  diaphragm. 

The  presence  of  flatus  in  the  stomach  and  intestinal  canal,  seems 
to  be  entirely  natural  to  them  ; for  it  is  comparatively  rare  to  find 
them  destitute  of  it,  even  when  they  contain  no  food  or  feces.  The 
large  intestine  is,  however,  more  frequently  found  contracted  or 
empty  than  the  small.  Owing  to  the  flexible  character  of  a con- 
siderable portion  of  the  abdominal  parietes,  the  latter,  by  their  own 
contraction,  as  well  as  by  atmospheric  pressure,  are  kept  in  close 
contact  with  the  viscera;  and  the  viscera  again,  by  the  same  influ- 
ence, are  kept  in  close  contact  with  one  another ; so  that,  notwith- 
standing the  irregularity  of  their  forms  and  the  fluctuating  size  of 
the  hollow  ones,  there  is  no  unoccupied  space  in  the  cavity  of  the 
belly. 

Several  instances  are  reported  by  anatomists,  in  which  a total 
transposition  of  the  abdominal  viscera,  has  occurred,  so  that  those 
which  belonged  to  the  right  side  were  placed  in  the  left.*  They 
are,  however,  exceedingly  rare.  In  the  entire  observation  of  my 
life,  amounting  to  thirty-five  years  of  anatomical  study,  and  extending 
itself  to  many  hundred  bodies,  I have  not  met  with  one  instance 
of  it. 

* Portal.  Haller.  Sandifort.,  &c. 


Vol.  II.— 3 


18 


ORGANS  OF  DIGESTION, 


CHAPTER  III. 

Of  the  Peritoneum,  and  Serous  Membranes,  Generally. 

SECT.  I. — OF  THE  PERITONEUM.* 

The  sides  of  the  abdomen  are  lined,  and  its  viscera  are  covered 
by  a membrane  called  Peritoneum.  As  the  reflections  of  this  mem- 
brane, by  being  thrown  over  the  periphery  of  almost  every  viscus  of 
the  abdomen,  consequently,  assume  the  same  shape;  and  as  it  lines, 
without  exception,  the  interior  surface  of  every  part  of  the  abdomen, 
its  form  is  extremely  complicated,  and  can  only  be  judged  of  accu- 
rately after  the  study  of  the  viscera  is  completed.  For  the  present 
it  will  only  be  necessary  to  give  the  outline  of  it,  leaving  the  details 
to  each  appropriate  occasion. 

In  man,  it  is  a complete  sac,  having  no  hole  in  it ; but  in  woman, 
its  cavity  communicates  externally  through  the  Fallopian  tubes.  It 
has  a double  use  : In  consequence  of  covering  the  viscera,  it  is  so 
reflected  from  them  to  the  sides  of  the  abdomen,  that  its  processes 
keep  the  viscera  in  their  proper  places,  and,  therefore,  answer  as 
ligaments:  again,  its  internal  surface  being  smooth,  indeed,  highly 
polished,  and  continually  lubricated  by  a thin,  albuminous  fluid,  cor- 
responding with  the  synovial  membrane  of  the  joints,  the  motions 
which  the  viscera  have  upon  each  other  in  exercise,  and  in  the  per- 
istaltic action  of  the  bowels,  are  much  facilitated. 

The  manner  in  which  a double  night-cap  is  applied  to  the  head, 
will  afford  the  easiest  conception  of  the  reflections  of  the  peritoneum. 
If  there  were  only  one  viscus  in  the  belly,  and  that  of  a somewhat 
regular  outline,  as  the  spleen,  the  comparison  would  be  rigid,  and 
perfectly  appreciable.  One  part  of  the  cap  is  close  to  the  head,  and 
compares  with  the  peritoneal  coat  of  the  spleen  ; the  other  is  loose, 
and  is  equivalent  to  the  peritoneum,  where  it  is  in  contact  with  the 
parietes  of  the  belly.  It  is  also  evident  from  this,  that  none  of  the 
viscera  can  be  said  to  be  within  the  cavity  of  the  peritoneum ; that 
they  are  all  on  its  outside  ; and  that  a viscus,  in  getting  a coat  from 


* Anat.  Atlas,  Fig.  298. 


OF  THE  PERITONEUM. 


19 


the  peritoneum,  merely  makes  a protrusion  into  its  cavity.  Start- 
ing with  this  simple  proposition,  it  is  easy  to  conceive  of  a second, 
a third  body,  and  so  on,  deriving  an  external  coat  from  a protrusion 
into  the  same  sac.  Admitting  these  bodies  to  be  spheres,  the  pro- 
position is  immediately  intelligible  ; and,  as  a last  step  from  it, 
the  idea  is  not  rendered  much  more  complex  by  substituting  any 
bodies  even  the  most  irregular  in  form,  for  these  spheres. 

Such,  then,  is  the  fact  in  regard  to  the  stomach,  intestines,  &c. ; 
they  all,  with  the  exceptions  to  be  stated,  derive  an  external  coat 
from  the  peritoneum. 

The  Peritoneum  is,  for  the  most  part,  smoothly  spread  upon  the 
interior  surface  of  the  abdominal  muscles.  It  adheres  to  them  with 
considerable  firmness  by  means  of  intervening  cellular  substance: 
this  adhesion,  where  it  closes  the  posterior  opening  of  the  umbilicus, 
is  unusually  strong.  Below,  the  uniformity  of  the  membrane  as  it 
descends  from  the  navel  to  the  pelvis  is  interrupted  by  its  being  re-^ 
fleeted  over  the  urachus,  and  over  the  remains  of  the  umbilical  artery 
on  each  side.  Where  the  urachus  is,  it  forms  an  oblong  prominent 
ridge,  reaching  to  the  upper  extremity  of  the  bladder ; and,  as  re- 
gards each  umbilical  artery,  the  duplicature  is  of  a variable  breadth 
in  different  individuals ; but  always  forms  a well  marked  falciform 
process,  reaching  from  near  the  umbilicus  to  the  lower  side  of  the 
bladder,  and  dividing  the  inguinal  region  into  two  parts  or  fossee, 
one  next  to  the  pubes,  and  the  other  near  to  the  ilium.  In  the  un- 
distended state  of  the  bladder  the  peritoneum  reaches  to  the  pubes, 
is  reflected  from  the  latter  to  the  upper,  and  then  goes  over  the  pos- 
terior surface  of  the  bladder.  In  the  male,  it  goes  from  the  posterior 
lower  end  of  the  bladder  to  the  rectum,  but,  in  the  female  it  does  not 
descend  so  low  there,  and  passes  from  the  bladder  to  the  vagina 
and  uterus,  and  afterwards  to  the  rectum. 

In  the  concavity  of  the  ilium,  and  in  the  lumbar  region,  the  peri- 
toneum is  attached  by  long  loose  cellular  substance,  which  permits 
it  to  be  stripped  off  easily,  simply  by  tearing.  In  these  several  re- 
gions it  encounters  the  colon,  over  which  it  is  reflected,  and  thereby 
forms  the  Mesocolon;  thence  it  passes  in  front  of  the  kidneys,  but 
separated  from  them  by  a thick  layer  of  cellular  and  adipose  matter, 
and  immediately  afterwards  it  is  thrown  into  a long  duplicature,  ex- 
tending obliquely  across  the  lumbar  vertebra  from  above,  down- 
wards, and  to  the  right  side.  This  duplicature  includes  the  small 
intestine,  and  is  the  Mesentery. 


20 


ORGANS  OF  DIGESTION. 


In  the  highest  regions  of  the  abdomen,  the  peritoneum  is  in  the 
greater  part  of  its  extent  uniformly  reflected  over  the  concave  surface 
of  the  diaphragm,  and  adheres  so  closely  to  it,  as  to  require  a cau- 
tious and  protracted  dissection  for  its  entire  removal.  As  the  re- 
mains of  the  umbilical  vein  of  the  foetus  are  still  found,  but  in  a 
ligamentous  condition,  going  from  the  navel  to  the  under  surface 
of  the  liver,  their  existence  gives  rise  to  the  falciform  ligament,  a 
broad  duplicature  of  peritoneum,  which  passes  from  the  upper  half 
of  the  linea  alba  and  from  the  middle  line  of  the  diaphragm  to  the 
liver.  Another  line  of  attachment,  or  of  reflection,  of  this  membrane 
to  the  liver,  is  found  all  along  the  posterior  margin  of  the  latter.  In 
the  same  region,  it  is  also  reflected  from  the  diaphragm  to  the  spleen 
and  to  the  stomach.  Such  is  the  general  account  of  the  course  of 
the  peritoneum.  Each  of  the  duplications  has  a distinct  name,  and 
some  peculiarity  of  organization  or  of  relation,  which  will  require 
a specific  description  and  a frequent  allusion  to  it. 

It  is  proved,  from  what  has  been  said,  that  the  peritoneum  is  a 
single  and  complete  sac,  and  that,  with  the  exception  stated  of  the 
Fallopian  tubes,  there  is  no  hole  in  it  either  for  the  passing  of  blood 
vessels,  nerves,  or  viscera.  And  that  it  is  so  folded  over  the  abdo- 
minal viscera,  that  with  patience  and  sufficient  address,  one  might 
remove  it  from  their  surface  and  extract  them,  without  even  laying 
open  its  cavity : an  experiment  said  to  have  been  successfully  ac- 
complished by  Nicholas  Massa,*  and  some  other  anatomists. 

SECT.  II.— OF  THE  OMENTA. f 

There  are  four  processes  of  the  peritoneum,  each  of  which  is 
designated  under  the  term  Omentum,  Epiploon,  or  Caul. 

1.  The  Omentum  Minus  or  Hepatico-Gastricum,  extends,  as  its 
name  imports  between  the  liver  and  the  stomach.  It  begins  at  the 
transverse  fissure  of  the  liver,  proceeds  from  it,  and  from  the  lobulus 
spigelii,  the  front  of  which  it  conceals;  and  then  continues  to  arise 
along  the  left  margin  of  the  base  of  this  lobule  to  the  back  part  of 
the  liver  until  it  reaches  the  diaphragm  ; it  also  arises  from  the  inferior 
face  of  the  tendinous  centre  of  the  diaphragm  along  its  posterior 

* Anat.  Liber  Introduce  an.  1539.  Portal, 
f Anat.  Atlas,  Fig.  999. 


OF  THE  OMENTA. 


21 


border,  by  its  lower  margin;  it  is  attached  to  the  lesser  curvature 
of  the  stomach  in  all  the  space  between  the  cardiac  and  the  pyloric 
orifice.  Its  right  margin  reaches  beyond  the  pylorus  to  the  duo- 
denum, and  includes  the  vessels  going  to  the  liver,  and  the  biliary 
ducts;  in  consequence  of  which,  this  margin  is  called  the  Capsule 
of  Glisson.  The  capsule  is,  however,  more  properly  the  condensed 
cellular  substance  within. 

The  two  laminae  which  compose  the  omentum  minus  are  thin  and 
transparent,  and  have  but  little  fat  in  them;  in  approaching  the 
stomach  they  become  very  distinct  from  each  other,  and  receive 
between  them  the  superior  coronary  vessels  of  the  stomach.  One 
lamina  then  goes  before  the  stomach  and  the  other  behind,  in  the 
form  of  a peritoneal  covering.  These  laminae,  having  covered  in 
that  way  the  anterior  and  the  posterior  surface  of  the  stomach,  unite 
again  on  the  greater  curvature  of  the  latter,  to  form  the  beginning 
of  the  omentum  majus. 

2.  The  Omentum  Majus  or  Gastro-Colicum,  as  indicated  by  its 
name,  is  connected  at  one  end  all  along  the  greater  curvature  of  the 
stomach,  and  by  the  other  along  the  transverse  part  of  the  colon. 
As  it  commences  by  two  laminae,  so  it  is  continued  throughout  in 
the  same  way.  It  is  commonly  found  more  or  less  spread  on  the 
front  surface  of  the  small  intestines,  but  occasionally  it  is  tucked  up 
in  the  epigastric  region.  When  fairly  spread  out,  either  naturally 
or  artificially,  its  course  will  be  found  as  follows:  It  first  of  all  de- 
scends from  the  stomach  to  the  pelvis;  it  then  turns  upwards,  so  as 
to  reverse  its  course,  and  continues  to  ascend  till  it  reaches  the 
colon.  Its  two  laminae  then  separate  and  receive  the  colon  between 
them,  so  that,  in  this  respect,  the  arrangement  is  entirely  conforma- 
ble to  what  happens  to  the  stomach.  The  subsequent  continuation 
of  these  laminae  is  the  mesocolon,  which  will  be  more  particularly 
described. 

As  the  omentum  majus  consists  of  two  laminae  in  its  whole  extent, 
it  is  clear  that  it  resembles  a flattened  bag  lined  by  another  bag;  so 
that  in  its  whole  thickness,  when  held  between  the  fingers,  there 
are  four  laminae.  It  is  an  irregular  quadrilateral  membrane,  which, 
in  corpulent  subjects,  is  interspersed  with  a great  deal  of  fat;  but  in 
such  as  are  emaciated,  it  is  wholly  destitute  of  the  latter;  and  instead 
of  being  entire  in  its  parietes  is  a delicate  reticulated  membrane,  so 
that  the  rule  about  the  integrity  of  the  peritoneum  is  not  fully  acr 

3* 


22 


ORGANS  OF  DIGESTION. 


curate  as  applied  to  this  section  of  it.  On  the  right  side  it  is  con- 
tinuous with  the  omentum  colicum,  and  on  the  left  with  the  omentum 
gastro-splenicum. 

3.  The  Omentum  Colicum  may  be  considered  as  a continuation 
of  the  omentum  majus  along  the  ascending  and  a part  of  the  trans- 
verse colon.  In  some  rare  cases,  (for  in  my  own  observations  I 
have  not  met  with  the  arrangement,)  its  origin  is  continued  down- 
wards to  the  ececum,  and  at  its  left  margin  is  extended  along  the 
transverse  colon  to  the  spleen.  Much  more  commonly  it  is,  as 
stated,  simply  an  appendage  of  the  great  omentum,  or  its  right 
flank,  advancing  for  a short  distance  along  the  ascending  colon. 

It  consists  of  but  two  laminae  in  all,  commonly  containing  fat,  but 
in  this  respect  subject  to  the  same  rule  as  the  omentum  majus. 

4.  The  Omentum  Gastro  Splenicum  is  the  left  flank  or  margin 
of  the  omentum  majus,  extended  from  the  great  end  of  the  stomach 
to  the  spleen.  It  of  course  consists  of  but  two  laminae,  which  con- 
tain between  them  the  splenic  vessels  and  the  vasa  brevia. 

By  looking  for  the  posterior  end  of  the  gall-bladder,  and  then 
passing  a finger  under  the  right  margin  of  the  hepatico-gastric  omen- 
tum, or  in  other  words,  under  the  capsule  of  Glisson,  where  it  ex- 
tends from  the  liver  to  the  duodenum,  the  finger  will  be  found  to 
have  insinuated  itself  behind  the  stomach,  and,  by  being  directed 
downwards,  will  be  thrust  into  the  sac  or  cavity  of  the  great  omen- 
tum. In  children,  where  the  latter  is  less  reticulated  than  in  adults, 
and  consequently  more  entire,  a large  blow-pipe  introduced  at  the 
same  point  will  enable  one  to  inflate  this  cavity,  and  to  separate  its 
anterior  from  its  posterior  wall.  This  aperture,  called  the  foramen 
of  Winslow,  is  the  route  by  which  the  internal  or  lining  lamina  of 
the  omentum  majus  is  introduced,  so  as  to  make  this  process  of  peri- 
toneum double  throughout  its  whole  parietes.  Though  this  fact  of 
duplicity  is  generally  conceded,  no  author  heretofore,  to  my  know- 
ledge, has  pointed  out  satisfactorily  the  means  ; and  for  the  sug- 
gestion of  it,  I am  indebted  to  a learned  and  zealous  member  of 
the  profession,  now  Professor  Hodge  of  the  University.  Struck,  at 
an  early  period  of  his  studies,  with  the  difficulty  of  tracing  a double 
sac  to  the  omentum  majus,  out  of  a single  membrane  of  the  peri- 
toneum, this  suggestion  was  happily  made  by  him  to  remove  the 
difficulties  of  other  explanations,  An  attempt  at  at  diagram  formed 


OF  THE  OMENTA. 


23 


upon  any  other  principle  I have  invariably  seen  to  fail.  If  the 
reader  has  conceived  the  idea,  the  inference  will  be  plain,  that  the 
lining  lamina  of  the  omentum  majus  is  continued  as  a common  peri- 
toneal covering  over  the  posterior  face  of  the  stomach,  and  then  forms 
the  posterior  lamina  of  the  hepatico-gastric  omentum.  It  will  also 
be  plain  that  the  same  lamina,  having  reached  the  colon  in  its  re- 
turn, continues  afterwards  as  the  upper  lamina  of  the  transverse 
mesocolon. 

From  wdiat  has  been  said  concerning  the  general  qualities  of  the 
peritoneum,  it  is  to  be  understood  that  though  it  enjoys  much  power 
of  gradual  extension,  nevertheless  this  quality  is  not  sufficient  to 
enable  it  to  endure,  without  a special  provision,  the  sudden  and 
extensive  dilatations  to  which  the  stomach  and  bowels  are  ex- 
posed, from  the  introduction  of  food  and  from  the  evolution  of  gases 
during  digestion.  Of  all  the  coats  of  these  organs,  it  is  the  least 
extensible  and  contractile  ; its  rupture,  therefore,  is  guarded  against 
by  one  invariable  rule.  For  example : as  the  muscular  and  other 
coats  of  the  stomach  dilate,  the  peritoneum  is  drawn  from  the  omen- 
tum minus  and  majus  to  cover  the  stomach  ; therefore,  as  the  sto- 
mach enlarges,  the  omenta  diminish:  and  as  the  stomach  decreases, 
the  omenta,  by  the  restoration  of  peritoneum,  resume  their  primi- 
tive size.  In  this  way  the  uterus,  notwithstanding  its  great  aug- 
mentation in  the  progress  of  pregnancy,  still  keeps  itself  covered  by 
peritoneum,  from  the  ability  of  the  latter,  as  mentioned,  to  slide 
from  one  part  and  to  apply  itself  to  another.  The  true  intention, 
then,  of  the  apparently  useless  length  of  many  processes  of  the  peri- 
toneum, is  explained,  by  their  being  a provision  for  the  augmenta- 
tion of  the  hollow  viscera  of  the  abdomen,  in  the  discharge  of  their 
natural  functions.  Adopting  this  explanation  as  the  basis  of  our 
observations,  we  shall  find  that  according  to  the  probable  or  even 
possible  augmentation  of  a viscus,  so  are  its  peritoneal  attachments. 
The  stomach,  which  next  to  the  uterus  enlarges  more  than  any  other 
viscus,  gets  its  subsidiary  supply  of  peritoneum  from  the  length  of 
the  omentum  minus  and  majus  ; the  colon,  which  is  next  in  order, 
is  supplied  from  the  length  of  its  mesocolon  ; the  small  intestines, 
which  are  next,  from  the  length  of  the  mesentery.  The  latter,  how- 
ever, would  be  too  long  for  that  simple  purpose  ; but  the  objection 
is  removed  by  recollecting  that  the  mesentery  has  also  to  accommo- 
date numerous  chains  of  lacteal  glands,  through  which  the  chyle 


24 


ORGANS  OF  DIGESTION. 


must  pass  in  its  elaboration,  before  it  is  fit  to  enter  into  the  general 
circulation.  The  liver,  being  of  a size  almost  stationary,  has  its 
peritoneal  attachments  proportionally  short ; and  its  peritoneal  co- 
vering, from  the  shortness  of  the  connecting  cellular  substance,  is 
disqualified  from  sliding.  The  spleen  is  in  the  same  predicament 
with  the  liver,  except  that  its  size  is  not  stationary  ; but  in  this 
case,  the  peritoneum  presents  a phenomenon  entirely  remarkable : 
it  wrinkles  upon  the  contraction  of  the  spleen. 

If  this  mode  of  reasoning,  derived,  from  an  arrangement  of  parts 
which  no  one  denies,  be  correct,  it  follows  that  physiologists  have 
erred  sadly  in  the  supposed  uses  of  the  omentum  majus.  That 
this  organ  is,  in  fact,  only  subsidiary  to  the  enlargement  of  the 
stomach  and  colon,  so  as  to  prevent  the  rupture  of  their  peritoneal 
coat,  and  that  it  is  neither  intended  to  keep  the  belly  warm,  as  so 
learned  a naturalist  as  M.  G.  Cuvier  has  suggested,*  nor  is  it  a 
special  store-house  for  the  wants  of  the  system  during  the  destitu- 
tion of  other  aliment,  farther  than  adipose  matter  in  other  parts  of 
the  body  is.f  In  regard  to  the  first  theory,  it  does  not  appear  that 
the  inhabitants  of  cold  climates  are  better  furnished  with  an  omen- 
tum majus  than  those  of  the  torrid  zone:  that  it  is  better  developed 
in  winter  than  it  is  in  summer ; that  it  is  tucked  up  in  warm 
weather  to  cool  the  intestines,  or  spread  out  in  cold  weather  to 
make  them  more  comfortable.  On  the  contrary,  it  is  ascertained 
that  its  position  is  variable  at  all  seasons  ; that  in  the  coldest  of 
wreather  it  is  as  often  found  collected  in  the  epigastric  region,  or  to 
one  side  of  the  abdomen,  as  it  is  in  the  warmest ; consequently,  its 
position  is  the  result  of  whatever  motions  may,  for  the  time,  have 
been  impressed  upon  it  by  the  distention  of  the  stomach,  and  by  the 
peristaltic  movements  of  the  bowels.  In  regard  to  the  theory  of  Dr. 
Rush,  this  objection  is  insurmountable  ; that  children,  who  are  equal- 
ly, if  not  more  exposed  to  starvation  and  sickness  than  adults,  never 
have  fat,  except  in  very  small  quantities,  in  the  omentum,  and  that 
only  along  the  course  of  its  vessels.  The  fat  is,  therefore,  not  to  be 
viewed  as  an  essential  circumstance  in  the  structure  of  the  omentum, 
as  all  children  and  many  adults  have  it  only  very  sparingly ; for  the 
omentum  bcimj  wanted  as  a membrane  of  reserve  to  the  stomach 
and  colon,  the  deposite  of  fat  in  it,  is  in  obedience  to  one  of  the 

* XXII.  Le«;on  D’Anat.  Comp. 

f An  Inquiry  into  the  Uses  of  the  Omentum,  by  .Tames  Rush,  Philad.  1809. 


HISTOLOGY  OF  SEROUS  MEMBRANES. 


25 


general  laws  of  the  system,  whereby  the  cellular  substance  beneath 
the  serous  membranes  is  disposed  to  secrete  fat  as  the  individual  ad- 
vances in  life ; which  is  exemplified  on  the  heart  and  in  the  pleura. 
Another  argument  is,  that  in  the  ruminating  animals,  where  there  are 
four  stomachs,  and  from  the  vegetable  nature  of  their  aliment  these 
stomachs  must,  in  the  course  of  digestion,  be  very  much  distended, 
the  great  omentum  is  of  proportionate  magnitude.* 

As  occurs  in  other  parts  of  the  body,  also,  the  fat  of  the  omen- 
tum accumulates  in  animals  that  take  but  little  exercise,  while  it  is 
very  deficient  in  such  as  lead  an  active  life. 

There  is  reason  to  believe,  that  the  hard  knots  felt  in  the  abdomen 
of  such  persons  as  suffer  from  abdominal  affections,  frequently  de- 
pend upon  the  accumulations  of  the  omentum  majus  at  particular 
but  variable  points. 

SECT.  III. — HISTOLOGY  OF  THE  SEItOUS  MEMBRANES. 

As  the  peritoneum  presents  one  of  the  best  examples  of  a nume- 
rous class  of  membranes,  called  Serous,  it  will  be  useful  at  this  point 
to  inquire  into  their  general  condition  and  properties.  They  are, 
for  the  most  part,  thin,  and  strongly  resemble  compressed  cellular 
membrane  ; having  been,  indeed,  by  some  anatomists,  considered  as 
such.  They  invariably  assume  the  form  of  perfect  sacs,  and  as  they 
are  found  in  all  parts  of  the  body,  they  are  kept  distinct  from  each 
other.  The  arachnoid  membrane  of  the  brain,  the  pericardium,  the 
pleura,  the  synovial  membranes  of  the  joints,  the  bursae  mucosae  of 
tendons,  the  peritoneum,  and  the  tunica  vaginalis  testis,  belong  to 
this  class.  They  are  not  all  of  the  same  thickness,  as  some  are 
much  more  dense  than  others  ; they  adhere  to  neighbouring  parts  by 
a lamina  of  cellular  substance,  which  is  also  of  variable  thickness 
and  ductility ; indeed,  on  some  occasions,  it  is  not  entirely  distinct, 
from  its  extreme  shortness  and  tenuity. 

As  the  serous  membranes  are  only  displayed  over  the  surface  of 
the  organs  which  they  cover,  after  the  manner  of  a double  night- 
cap drawn  over  the  head ; their  cavity  always  remains  entire,  not- 
withstanding it  is  variously  modified  by  the  shape  of  the  organs 
protruded  into  it ; and  has  its  parietes  in  contact,  owing  to  external 
compression.  They  are  entirely  distinct  from  the  essential  struc- 
ture of  the  organs  covered,  and  are  displayed  over  those  of  the  most 

* Cuvier,  XXII.  Legon.  loc.  cit. 


26 


ORGANS  OF  DIGESTION. 


dissimilar  functions,  as,  for  example,  the  intestines  and  the  liver. 
A sac  of  this  description,  then,  is  of  infinite  importance  in  establish- 
ing between  organs  which  border  upon  one  another  a strong  par- 
tition; and,  consequently  in  warding  off  any  injurious  influence 
which  their  dissimilar  natures  would  otherwise  cause  them  to  have 
upon  each  other.  Important  organs  are,  therefore,  invariably  thus 
insulated,  so  that  whether  in  a healthy  or  in  a diseased  state,  their 
actions  are  carried  on  within  themselves ; and  not  only  so,  but  it  is 
even  possible,  and,  indeed,  is  found  in  morbid  dissections,  every  day, 
that  an  organ  may  be  diseased  while  its  serous  covering  is  unaf- 
fected ; or  the  reverse.  Thus,  we  have  large  suppurations  in  the 
liver,  while  its  peritoneal  coat  is  healthy  ; large  accumulations  of 
water  in  the  tunica  vaginalis  testis,  while  the  testicle  itself  is  sound  ; 
in  the  thorax,  with  sound  lungs  and  heart;  in  the  abdomen,  with 
viscera  generally  sound ; in  the  joints,  without  an  affection  of  the 
bones.  Nothing  is  more  common  than  to  see  partial  adhesions,  the 
result  of  inflammation,  causing  the  opposite  sides  of  these  sacs  to 
adhere,  without  any  evident  constitutional  or  visceral  derangement ; 
and  some  of  our  plans  of  cure,  as  in  the  hydrocele,  are  founded 
upon  this  well  established  fact. 

The  serous  membranes  are  throughout  thin,  transparent,  and 
white : in  some  points  their  tenuity  is  so  extreme  that  they  seem  to 
consist  simply  in  a smooth,  polished  surface,  spread  over  parts  ; this 
is  strikingly  the  case  on  the  interior  face  of  the  dura  mater,  on  the 
ventricles  of  the  brain,  and  on  the  cartilages  of  the  joints.  The 
evidence  of  their  extension  there,  is  consequently  derived  principally 
from  induction;  and  from  morbid  alteration,  in  which  they  become 
thickened.  Their  internal  surface  in  a natural  state,  is  always 
smooth,  highly  polished,  shining  ; and,  being  also  lubricated  by  its 
peculiar  unctuous  secretion,  the  opposite  parietes,  when  they  come 
into  contact,  glide  freely  upon  each  other  ; a circumstance  indispen- 
sable to  the  free  action  of  the  joints,  and  to  the  peristaltic  motion  of 
the  bowels.  Bordeu  has  asserted,  that  these  remarkable  characters 
of  the  serous  membranes  depend  upon  the  compression  and  the 
friction  to  which  they  are  continually  exposed:  but  to  this  opinion  the 
argument  of  Bichat  is  unanswerable,  that  in  their  earliest  observable 
period  in  the  foetus  they  have  the  same  polish. 

The  fluid  secreted  from  the  serous  membranes  resembles,  strongly, 
tire  serosity  of  the  blood.  It  is  poured  out  continually  by  the  exha- 
lant  orifices,  and  in  a short  time  afterwards,  is  taken  up  by  the  ab- 


HISTOLOGY  OF  SEKOUS  MEMBRANES. 


sorbents ; so  that  in  a natural  state  there  is  seldom  more  than  suffi- 
cient to  lubricate  the  surface  of  the  membrane.  When  the  abdomen 
of  an  animal,  recently  killed,  is  exposed  to  the  air,  this  fluid  rises  in 
tire  form  of  a vapour.  The  several  experiments,  as  the  application 
of  heat,  mineral  acids,  and  so  on,  which  prove  the  abundarBe  of 
albumen  in  the  serum  of  the  blood,  produce  the  same  resultsBhen 
applied  to  the  secretion  from  the  serous  membranes. 

The  system  of  serous  membranes  has  been  considered  by  Bichat 
and  others,  as  only  a modification  of  cellular  membrane,  for  the 
following  reasons.  The  inflation  of  air  into  the  cellular  tissue  sub- 
jacent to  them,  reduces  them  to  the  form  of  cellular  substance. 
Protracted  maceration  produces  the  same  effects  with  more  certainty 
and  precision.  When  cellular  membrane  is  inflated,  the  parietes  of 
the  distended  cells  resemble  strongly  the  finest  parts  of  the  serous 
system,  as  the  arachnoid  membrane.  There  is  an  identity  of  func- 
tions and  of  affections,  for  they  are  both  continually  engaged  in  the 
great  work  of  exhalation  and  absorption,  and  suffer  in  the  same  way 
from  dropsical  effusion,  with  the  only  difference  that  the  latter  is  more 
amassed  in  the  one  than  in  the  other.  My  own  experience  goes  to 
prove,  that  dropsy  very  seldom  manifests  itself,  to  any  extent,  in  the 
cellular  tissue  without  also  going  to  the  serous  cavities,  and  the  re- 
verse. The  serous  membranes  are  also  of  a uniform  texture,  like 
cellular  substance;  and  present  no  appearance  of  a fibrous  matter. 

The  serous  membranes  are  furnished  with  a great  abundance  of 
exhalant  pores,  and  of  absorbents,  which  carry  on  their  functions 
with  great  activity.  They,  when  healthy,  receive  only  the  colour- 
less part  of  the  blood,  whence  the  uniform  transparency  of  these 
membranes.  The  existence  of  exhalant  pores,  is  proved  by  stran- 
gulating a piece  of  intestine  with  a ligature  for  thirty-six  or  forty- 
eight  hours,  when  they  become  evident,  by  dilating  themselves  so 
as  to  receive  red  blood.  A fine  coloured  injection  produces  the 
same  result ; and  also  moistens,  by  the  escape  of  its  watery  particles, 
the  surface  of  the  intestine,  by  a very  fine  halitus  or  dew.  The 
intestine  of  a living  animal,  if  wiped  perfectly  dry,  will,  after  the 
same  way,  soon  present  another  coat  of  serosity  on  its  surface.  The 
existence  of  absorbents  to  a great  extent  in  them,  may  also  be  equally 
well  proved,  as  they  very  readily  receive  a mercurial  injection,  which 
diffuses  itself  over  their  whole  surface,  and  causes  them  to  have  the 
appearance  of  being  formed  entirely  of  such  vessels.  The  readi- 
ness with  which  fluid  effused  into  their  cavities  is  taken  up,  is  another 


/ 


m 

•28 


ORGANS  OF  DIGESTION. 


proof  of  the  same.  Bichat  once  saw  them  distended  with  air  in  a 
man  who  had  become  emphysematous  from  poisoning.  Mascagni 
has  frequently  found  them  distended  with  the  fluid  of  dropsical  col- 
lections, which  he  recognised  by  its  colour.  It  happened  to  the 
same  anatomist  to  find  in  two  bodies,  where  there  had  been  an  ef- 
fusion of  blood  into  the  thorax,  the  absorbents  of  the  lungs  gorged 
with  blood.  This  faculty  of  absorption  may  sometimes  be  proved 
to  continue  for  some  hours  after  death,  by  keeping  an  animal  in  a 
warm  bath.  Mascagni  asserts,  that  he  has  witnessed  its  continuance 
for  fifteen,  thirty,  and  even  for  forty-eight  hours ; it  is  not  improba- 
ble, however,  that  there  was  some  illusion  in  these  instances. 

In  a preparation  made  by  myself  of  the  peritoneal  coat  of  the 
stomach,  pores  giving  this  membrane  a cribriform  condition  are  very 
visible;  and  Dr.  Leidy,  to  whom  I am  indebted  for  a drawing  of  the 
same,  has  the  facility  of  detecting,  by  the  naked  eye,  similar  pores 
over  the  whole  peritoneum.  Whether  these  pores  are  exhalant  or 
absorbent,  I have  not  yet  ascertained.*  They,  by  their  uniformity 
and  smoothness,  bear  every  indication  of  being  organized  pores. 
If  a similar  arrangement  exist  every  where  over  the  entire  extent 
of  serous  membranes,  it  is  not  an  unreasonable  conjecture  to  con- 
sider them  as  absorbing  orifices,  and  thus  to  explain,  the  high 
absorbent  powers  of  such  membranes.  These  orifices  are  most 
probably  formed  by  meshes  of  lymphatics;  as  upon  the  mucous  sur- 
face of  the  gastro-intestinal  mucous  membrane,  the  Follicles  of 
Lieberkuhn,  or  the  gastro-enteric  follicles,  are  formed  by  meshes  of 
veins.  As  serous  membranes  are  also  furnished  with  their  Epithe- 
lium, hence,  when  it  is  raised  by  insufflation,  the  air  does  not 
escape  through  these  pores. 

It  is  more  than  probable  that  the  serous  membranes  are  entirely 
deprived  of  red  blood  vessels  ; the  latter  unquestionably  exist,  in 
great  numbers,  on  the  exterior  surface,  where  they  creep  through 
the  cellular  substance,  but  they  may  be  removed  with  a scalpel 
without  affecting  the  continuity  of  these  membranes.  Again,  where 
these  membranes  are  free  and  unconnected  on  both  surfaces,  as  in 
some  parts  of  the  tunica  arachnoidea,  there  is  no  appearance  of  red 
blood  vessels.  In  hernial  protrusions,  where  there  is  a considerable 
prolapse  of  peritoneum,  the  blood  vessels  which  are  found  abundantly 
about  the  neck  of  the  sac  do  not  follow  out  the  course  of  the  protrusion. 
Unquestionably  some  communication  exists  between  the  arterial  sys- 


* See  Plate,  article,  Stomach. 


HISTOLOGY  OF  SEROUS  MEMBRANES. 


29 


lem  and  the  serous  membranes,  as  proved  by  exhalation  and  morbid 
phenomena,  but  the  mode  is  not  well  ascertained.  We  learn,  how- 
ever, upon  the  authority  of  Muller,#  that  there  are  some  preparations 
of  the  peritoneum  by  Bleuland  at  Utrecht, — and  some  also  by.Der 
Kolk,  of  the  same  membrane,  which  prove  indubitably  that  -this 
membrane  contains  vessels. 

In  common  hernia  and  in  dropsy,  the  serous  membranes  become 
more  thick : from  my  dissections  I am  inclined  to  think,  that  this 
change  is  not  so  great  as  is  generally  allowed ; for  most  frequently, 
by  a careful  removal  of  the  exterior  cellular  substance,  they  have 
been  restored  to  their  primitive  condition.  In  other  cases,  as  in 
large  umbilical  herniae,  they  are  so  much  attenuated  as  to  be  found 
with  difficulty. 

The  power  of  extension  which  these  membranes  possess,  is  strik- 
ingly marked  in  dropsical  effusions,  in  the  development  of  tumours, 
and  in  pregnancy ; but  much  of  this  apparent  quality  is  derived  from 
their  mode  of  attachment  to  adjacent  parts,  whereby  they  are  drawm 
from  one  surface  to  cover  another.  This  happens  daily  wffiere  the 
peritoneum  is  drawn  from  the  lowmr  part  of  the  abdomen  to  cover 
the  bladder  in  the  distentions  of  the  latter;  in  pregnancy,  where  it 
is  drawn  upon  the  growing  uterus  from  all  the  neighbouring  parts  ; 
and  in  the  distentions  of  the  stomach  by  food  or  flatus,  where  it  is 
drawn  up  from  the  omenta.  The  serous  membranes  have  also  a 
power  of  contraction  equal  to  that  of  their  extension ; but  it  should 
not  be  confounded  with  that  condition  where  they  are  simply  restored 
by  the  connecting  cellular  substance,  to  the  surfaces  to  which  they 
originally  belonged. 

The  sensibility  of  the  serous  membranes,  is  extremely  obscure  in 
a natural  state,  and  only  affords  an  imperfect  sensation  of  touch. 
This  is  proved  by  the  impunity  with  which  they  may  be  irritated  on 
living  animals.  This  has  generally  been  attributed  to  the  want  of 
nerves,  which  however  have  been  lately  traced  into  the  pia  mater 
and  arachnoid  by  Purkinje  and  Rainy — and  into  the  peritoneum  and 
pleura  by  Bougery.  But,  when  the  condition  of  inflammation  is  once 
established,  they  feel  the  most  acute  and  distressing  pain.  Though 
they  resist  most  frequently,  and  for  a long  time,  disease  in  adjacent 
parts,  yet  it  not  unfrequently  is  extended  to  them  at  last.  In  such 
cases,  it  is  generally  a local  instead  of  a universal  affection,  which 

* Physiol,  p.  226. 

Vol.  II.— 4 


V 


30 


ORGANS  OF  DIGESTION. 


is  communicated  to  them : Thus,  in  the  cancer  and  scirrhus  of  the 
uterus;  in  disease  of  the  spleen,  and  so  on;  the  portion  of  perito- 
neum nearest  the  affected  organ  manifests  the  marks  of  the  disease 
by  meter natural  adhesions  and  by  disorganization,  without  the  whole 
membrane  being  involved. 

As  the  serous  system  consists  in  many  species  of  sacs,  so  each  of 
them  has  some  peculiarity  of  organization,  of  attachment,  and  of  vital 
properties,  which  is  stated  elsewhere  in  the  account  of  the  species 
themselves. 

By  acting  on  the  inner  surface  of  a bivalve  shell  with  dilute  acid 
a very  thin  pellicle  is  raised  of  a structure  so  uniform  and  so  destitute 
of  organic  arrangement  that  it  resembles  more  the  walls  of  a soap 
bubble,  and  it  is  hence  defined  as  being  amorphous  or  structureless. 
In  some  parts  of  the  human  body  the  same  exists,  in  others  it  is 
modified  by  being  granular,  and  in  others  again  by  being  covered  with 
epithelial  scales.  This  membrane,  wherever  found,  has  been  desig- 
nated by  Messrs.  Bowman  and  Goodsir  as  a basement  or  primary 
membrane,  and  is  supposed  by  them  to  be  the  matrix  of  the  epithelial 
scales,  which  are  successively  evolved  from  its  free  surface,  if  it  does 
not  itself  undergo  a constant  disintegration  and  renewal.  The  peri- 
toneum with  all  other  serous  cavities  is  considered  to  be  lined  by 
such  basement  membrane  in  some  one  of  the  conditions  indicated. 

The  microscope  has  thus  proved  that  notwithstanding  the  extremely 
polished  surface  of  the  free  side  of  the  serous  membranes,  yet  they 
are  covered  by  an  epithelium,  which  epithelium  has  been  found  on 
all  except  the  sub-cutaneous  bursse.  Reichert  indeed  has  described 
an  epithelium  upon  the  interior  surface  of  the  tendinous  and  of  the 
subcutaneous  bursse,  like  that  of  the  arteries  and  of  the  true  serous 
membranes.*  The  epithelium  of  the  serous  cavities  is,  like  the  epi- 
dermis, formed  of  flattened  scale-like  cells,  which  are,  for  the  most 
part,  polygonal  or  tesselated,  like  a pavement  made  of  hexagonal 
bricks,  and  have  each  a nucleus  in  their  centre.  Some  of  these  cells 
are  furnished  at  their  edges  with  minute  hair-like  filaments  called 
cilia,  which,  during  life  and  for  some  time  after  death,  are  in  a state 
of  continual  whirling  or  vibration,  and  as  is  supposed,  for  the  pur- 
pose of  preventing  a stagnation  of  the  fluids  in  contact  with  them. 
These  cilia  are  especially  numerous  and  active  in  the  ventricles  of 
the  brain.  In  some  places  the  epithelium  is  found  without  the  serous 


* Muller,  Arch.  1844 


THE  STOMACH. 


31 


membrane  beneath,  hence  it  is  inferred  that  the  latter  is  not  so  essen- 
tial as  the  former  in  the  character  of  such  membranes. 

These  epithelia  being  always  in  contact  with  fluids,  they  differ 
from  the  cuticle  by  being  pliant  and  humid ; but  are  restored  with 
equal  facility  when  they  are  lost  by  abrasion  or  inflammation. 


CHAPTER  IV. 

Of  the  Chylopoietic  Viscera. 

SECT.  I. — OF  THE  STOMACH.* 

The  Stomach  ( Ventriculus , Stomachics ) is  a hollow7  viscus  situ- 
ated in  the  epigastric  region,  intended  to  receive  at  one  end  alimen- 
tary matters  from  the  oesophagus,  and  to  transmit  them,  at  its  other 
extremity,  after  digestion,  into  the  intestinal  tube,  where  the  nutri- 
tious part  of  the  food  is  absorbed  into  the  circulation.  It  is  a co- 
noidal  sac,  curved  considerably  upwards,  and  presents  two  Faces, 
two  Orifices,  two  Curvatures,  and  two  Extremities. 

The  Faces  of  the  stomach  are,  from  their  position,  named  ante- 
rior and  posterior,  or,  one  presents  to  the  linea  alba  and  the  other 
towards  the  spine.  The  flat  configuration  is  rendered  more  obvious 
when  the  organ  is  empty ; for  when  distended  it  is  rounded,  and 
the  anterior  face  is  caused  to  look  forwards  and  upwards  from  the 
resistance  of  the  spine  behind,  while  the  posterior  is  of  course  in  an 
opposite  direction.  In  other  respects  they  do  not  present  any  thing 
worthy  of  particular  attention. f 

The  two  Orifices  of  the  stomach  are  named  Cardia  and  Pylorus. 
The  first  or  Cardia  is  at  the  left  and  most  superior  part,  but  removed 
to  the  distance  of  two  inches  or  more  from  the  left  extremity.  It 
is  generally  considered  a smooth  uninterrupted  continuation  of  the 
oesophagus  into  the  stomach,  immediately  after  the  oesophagus  has 
passed  through  the  diaphragm  into  the  abdomen.  But  in  a prepara- 
tion, of  this  organ,  made  by  drying, J and  now  in  the  anatomical 

* Anat.  Atlas,  Fig.  303  to  309,  inclusive. 

f In  some  cases  the  posterior  face  of  the  stomach  is  concave  to  accommodate 
it  to  the  spine  . this  is  best  seen  on  inflation  and  drying. 

^ December,  1828. 


32 


ORGANS  OR  DIGESTION. 


cabinet,  a circular  rounded  pad  is  very  perceptible  at  the  cardiac 
orifice  ; being  elevated  two  lines  or  more  all  around,  so  that  it  makes 
a perfect  ring  of  from  eight  to  twelve  lines  broad  at  its  base.  This 
pad  seems  to-  be  composed  of  a cellular  substance,  which  is  almost 
perfectly  white,  elastic,  and  consists  of  the  finest  filaments,  resem- 
bling carded  cotton : it  is  placed  between  the  lining  membrane  of 
the  cardiac  orifice  and  the  adjoining  coat. 

The  Pylorus,  when  viewed  externally,  looks  like  a smooth  con- 
tinuation of  the  stomach  into  the  duodenum  ; but  when  felt,  there 
is  a manifest  thickening  of  the  part,  depending  upon  a structure  to 
be  presently  explained.  It  points  upwards  and  to  the  left  side, 
but  is,  by  the  whole  thickness  of  the  liver,  lower  down  than  the 
cardia. 

The  two  Curvatures  are  designated  the  great  and  small,  or  the 
upper  and  the  lower.  The  first,  forming  the  upper  margin  of  the 
stomach,  is  bounded  at  its  extremities  by  the  orifices,  and  is  very 
concave  ; its  curvature  is  maintained  both  by  a natural  configuration 
and  by  the  small  omentum.  The  great  curvature  forms  the  whole 
inferior  periphery  of  the  organ,  extending  also  from  one  orifice  to 
the  other.  When  the  stomach  is  flattened,  these  curvatures  form 
very  evident  boundaries  to  the  anterior  and  the  posterior  face. 

The  Extremities  of  this  organ  are  remarkably  different  in  size. 
That  to  the  left  forms  the  base  of  the  cone,  or  the  large  extremity, 
and  projects  considerably  beyond  the  cardia  towards  the  spleen. 
It  is  a rounded  cul-de-sac,  or  tuberosity,  the  dimensions  of  which 
will,  of  course,  vary  according  to  the  state  of  distention.  The  right 
extremity,  on  the  contrary,  is  produced  by  a gradual  diminution  of 
the  organ  from  its  middle  to  the  duodenum.  When  the  stomach 
has  approached  within  an  inch  or  two  of  the  latter,  it  suffers  a sort 
of  constriction,  which  gives  to  the  right  end  a more  cylindrical  shape. 
This  part  is  sometimes  called  the  Little  cul-de-sac,  or  the  Antrum 
pylori. 

When  the  stomach  has  been  kept  empty  for  some  time  previous  to 
death,  it  is  found  not  much  larger  than  an  intestine  ; its  variable 
magnitude,  therefore,  prevents  any  very  rigid  rule  of  dimensions 
from  being  applied  to  it ; most  commonly,  however,  we  find  it  be- 
tween the  capaciousness  of  a pint  and  of  a quart  measure. 

It  is  retained  in  its  situation  by  its  continuity  with  the  oesophagus 
and  duodenum ; also  by  the  hepatico-gastrio,  and  the  gastro-splenic 
omentum.  It  is  in  contact  above,  at  its  lesser  curvature,  with  the 


THE  STOMACH. 


33 


diaphragm,  the  left  lobe  of  the  liver,  and  the  lobulus  Spigelii ; at  its 
great  extremity  with  the  spleen,  .at  its  posterior  face  with  the  pan- 
creas, and  at  its  greater  curvature,  with  the  colon  and  the  mesocolon. 

The  stomach  is  formed  by  four  Coats  or  laminae,  of  a character 
essentially  differing  from  each  other : The  Peritoneal,  the  Muscular, 
the  Nervous,  and  the  Mucous. 

The  Peritoneal  Coat  envelops  the  stomach  completely,  and  ad- 
heres closely,  except  at  the  curvatures,  where,  as  has  been  men- 
tioned, a provision  is  made  for  the  distention  of  the  organ,  by  the 
looseness  and  the  separability  of  the  attachment  of  the  two  laminae 
of  the  omentum  minus  and  of  the  majus.  An  uncovered  space  will, 
consequently,  be  found  between  the  laminae  at  these  places,  along 
which  the  vessels  run  that  furnish  the  stomach.  The  peritoneal  coat 
is  very  thin,  and  is  attached  to  the  subjacent  muscular,  by  very  fine 
cellular  substance,  which  permits  it  to  be  raised  from  the  muscular 
by  a careful  dissection.  In  a dried  preparation  which  I made,* 
there  is  an  exhibition  of  minute  foramina  of  the  peritoneal  coat,  in 
apposition  nearly  as  close  as  the  follicles  of  the  mucous  coat.  Already 
alluded  to  in  the  article  on  serous  membranes,  the  attending  plate, 
the  drawing  for  which  was  made  by  Dr.  Leidy  from  nature,  exhibits 
well  the  appearance  of  the  piece. 


The  Muscular  Coat  is  intermediate  in  thick- 
ness to  that  of  the  intestines  and  of  the  oeso- 
phagus, but  its  fibres  are  pale,  are  collected 
into  flattened  fasciculi,  and  go  in  three  direc- 
tions. The  most  superficial  are  a continua- 
tion of  the  longitudinal  fibres  of  the  oesopha- 
gus, and  are  less  numerous  and  less  uniform 
in  their  distribution  than  the  circular  fibres, 
The  greater  part  of  them  forms  a flattened 
broad  fasciculus,  which  extends  along  the 
lesser  curvature  of  the  stomach,  from  the  car- 
diac to  the  pyloric  orifice.  A thinner  and  less 
distinct  fasciculus  may  be  traced  over  the  great 
cul-de-sac,  and  somewhat  indistinctly,  along 


Organized  pores  in 
Serous  coat  of  Stomach 
from  the  1,40  to  the  1,8 
of  a line  in  diameter,  by 
nature. 

the  greater  curvature  : 


* In  1839. 
4* 


34 


ORGANS  OF  DIGESTION. 


aiul  a few  others  may  be  seen  on  the  anterior  and  posterior  faces  of 
the  stomach  forming  rather  a fine  linear  or  striated  appearance  than 
a perfect  lamina ; this  linear  appearance  is  well  exhibited  by  an 
oblique  reflection  of  light  from  it.  The  second  series  consists  in  a 
lamina  of  circular  fibres  distinctly  covering  the  whole  surface  of  the 
organ.  They  are  not  so  numerous  near  the  cardia,  but  become  more 
abundant  as  they  are  examined  towards  the  pylorus,  in  the  vicinity 
of  which  they  are  multiplied  so  as  to  form  a lamina  of  two  lines  or 
more  in  thickness.  The  circular  fibres  are  parallel  with  each  other, 
and,  when  the  stomach  is  much  distended,  their  fasciculi  separate  so 
as  to  leave  interstices  between  them  in  many  places.  The  indi- 
vidual fibres  do  not  surround  entirely  the  stomach,  but  are  rather 
segments  of  circles.  The  third  and  deepest  series  of  fibres,  consti- 
tuting the  muscle  of  Gavard,  from  their  discoverer,  may  be  called 
oblique,  and  are  arranged  into  two  broad  flattened  fasciculi,  one  of 
which  is  placed  to  the  left  side  of  the  cardia,  and  is  prolonged  over 
the  anterior  and  the  posterior  face  of  the  stomach ; while  the  other, 
being  to  the  right  of  the  same  orifice,  is  extended  over  the  anterior 
and  the  posterior  face  of  the  cul-de-sac,  where  it  supplies  the  want 
of  transverse  or  circular  fibres : this  series  may  be  considered  as  a 
continuation  of  the  circular  fibres  of  the  oesophagus. 

The  Nervous  or  Cellular  Coat  ( Tunica  Propria ,)  connects  the 
muscular  with  the  mucous.  It  is  formed  by  a compact,  thick,  and 
short  cellular  substance,  which  when  inflated  and  dried,  looks  like 
carded  cotton.  It  contributes  much  to  the  general  strength  of  the 
organ,  and  serves  to  conduct  the  blood  vessels  and  the  nerves  to  the 
mucous  coat. 

The  Mucous  or  Villous  Coat  is  the  most  internal,  is  not  quite  a 
line  in  thickness,  and  can  be  readily  raised  up  by  dissection.  In 
an  undistended  state  of  the  stomach  it  is  arranged  into  a number  of 
wrinkles,  which  are  very  irregular  in  their  form,  size,  and  direction, 
but  disappear  immediately  on  distention,  or  at  least  leave  but  very 
faint  traces.  It  is  continuous  with  the  internal  membrane  of  the 
(esophagus  and  duodenum,  but  presents  a surface  differing  from 
either  of  them,  and  which  is  rendered  very  apparent  by  floating  it 
in  water.  The  epidermis,  which  is  continued  along  the  internal 
face  of  the  oesophagus,  ceases  as  mentioned  around  the  cardiac  ori- 
fice, and,  by  a slight  maceration  maybe  raised  up  and  demonstrated 


THE  STOMACH. 


35 


to  terminate  there.  An  epithelium  under  modified  circumstances  is 
then  found  to  start  and  to  cover  the  entire  interior  of  the  stomach, 
and  to  be  continued  over  the  intestinal  canal  from  one  end  to  the  other. 

It  is  softer,  thinner,  and  more  spongy  than  the  common  epidermis 
of  the  pharynx  and  oesophagus,  but  may  be  proved  to  exist  by  the 
microscope,  by  the  exfoliations  in  scales  found  in  the  feces,  and 
also  by  insufflation,  when  it  will  be  raised  and  may  be  dried  in  that 
state. 

This  mucous  membrane  or  coat,  the  office  of  which  is  to  secrete 
the  gastric  juice  for  the  digestion  of  articles  of  food,  presents  a sur- 
face that  resembles  very  much  common  velvet,  from  whence  the  term 
villous  is  applied  to  it.  If  it  be  perfectly  healthy,  and  the  individual 
died  suddenly  a few  hours  after  eating' — -it  is  found  of  a uniform  light 
pink  colour,  without  blotches  or  anything  of  extravasation  under  it. 
This  fact  I have  had  several  opportunities  of  verifying,  by  experi- 
ment and  by  autopsies  :*  And  more  lately  in  the  person  of  a crimi- 
nal, Williams,  executed  for  murder. f It  is  usual,  to  find  it,  if  ex- 
amined a short  time  after  death,  having,  particularly  along  the  smaller 
curvature  and  at  the  great  end,  a pink  and  sometimes  a deeper 
colour,  produced  by  an  accumulation  of  blood  in  its  veins. 

The  texture  of  this  membrane  is  soft,  loose,  and  easily  lacerated. 
When  floated  in  water  and  examined  with  a magnifying  glass,  it  is 
found  to  have  a superficial  honey-comb  arrangement,  and  to  be 
studded  with  a multitude  of  small  follicles  or  orifices  whose  number 
is  above  fourteen  thousand  to  the  square  inch,  and  whose  diameter 
varies  from  the  fortieth  to  the  eighth  of  a line.  In  the  vicinity  of  the 
cardiac  and  of  the  pyloric  orifice,  the  same  arrangement  is  more  ob- 
vious, and  exhibits  also  some  small  glands,  which  are  more  or  less 
apparent,  and  called  the  glands  of  Brunner,  being  by  some  con- 
sidered muciparous  and  by  others  as  the  source  of  the  gastric  fluid. £ 

At  the  junction  of  the  lesser  extremity  of  the  stomach  with  the 
duodenum,  the  internal  membrane  is  thrown  into  a circular  dupli- 
cature  constituting  the  Pyloric  valve,  and  abridging  the  size  of  the 
orifice.  It  is  seen  most  favourably  in  the  distended  and  dried  state, 
and  then  presents  a sort  of  septum  not  unlike  the  form  of  the  iris. 
Around  the  external  periphery  of  this  ring,  the  circular  muscular 
fibres  have  an  abrupt  augmentation  of  number,  which  gives  them, 

* See  Amer.  Journal  Med.  Sciences,  Yol.  i.  1827.  Horner’s  Pathol.  Anat» 
p.  195,  &c. 

f Aug.  9,  1839.  \ Anat.  Atlas,  Fig.  311.. 


36 


ORGANS  OF  DIGESTION. 


when  viewed  from  the  duodenum,  the  appearance  of  a distinct  cir- 
cular muscle,  occasionally  called  the  muscle  of  the  pylorus,  but  it 
does  not  exist  in  a state  so  separate  as  this  name  indicates.  The 
opening  of  the  pyloric  valve  is  generally  circular,  but  sometimes 
ovoidal,  and  it  is  sometimes  to  one  side. 

It  is  very  common  to  find  the  stomach  divided  as  it  were  into 
two  compartments,  by  a contraction  of  its  middle,  resembling  that 
of  an  hour  glass.  It  is  said  that  this  occurs  habitually  during  diges- 
tion ; in  my  personal  observations,  however,  I have  seen  the  stomach 
more  frequently  in  this  state  when  it  contained  nothing,  not  even  air, 
than  when  articles  of  aliment  were  in  it. 

The  stomach  is  extremely  vascular.  Its  arteries,  being  branches 
of  the  Cceliac ; are  the  Gastric,  the  Right,  and  the  Left  Gastro- 
Epiploic,  and  the  Vasa  Brevia.  The  first 
goes  along  its  lesser  curvature,  the  second 
and  the  third  along  its  greater  curvature, 
and  the  last,  from  four  to  six  in  number,  go 
to  its  great  cul-de-sac.  They  all  approach 
it  between  the  laminae  of  its  omenta,  and 
undergo  many  divisions  and  subdivisions 
in  the  cellular  coat;  they  at  length  termi- 
nate by  forming  a very  fine  and  delicate 
vascular  arrangement  in  the  substance  of 
the  mucous  membrane,  and  when  success- 
fully injected  give  to  the  latter  a thorough 
tinge  of  red.  The  veins  follow  the  course 
of  the  arteries,  and  like  them  have  frequent 
anastomoses,  but  are  larger ; they  terminate 
either  directly  or  indirectly  in  the  trunk 
of  the  Vena  Portarum.  The  attending 
plate  drawn  by  Dr.  Leidy  from  an  injection  of  mine,  exhibits  the  veins 
of  the  stomach  as  seen  with  a microscope,  on  the  mucous  coat. 

The  nerves  of  the  stomach  come  from  the  Par  Vagum,  and  from 
the  semi-lunar  ganglions  of  the  Sympathetics. 

Its  lymphatics  arise  from  both  the  external  and  the  internal  sur- 
face, and  their  trunks  having  to  pass  first  of  all  to  the  lymphatic 
glands  situated  along  the  curvatures,  afterwards  empty  into  the  tho- 
racic duct. 


Fig.  22. 


Reticular  arrangement  of 
veins  to  form  the  mouths 
of  the  mucous  follicles  of 
the  stomach.  Natural  dia- 
meter of  meshes  from  the 
1-40  to  the  1-8  of  a 4-ine  in 
diameter. 


INTESTINAL  CANAL. 


37 


SECT.  II. — OF  THE  INTESTINAL  CANAL. 

The  Intestinal  Canal  is  from  thirty  to  thirty-five  feet  in  length, 
and  extends  from  the  pylorus  to  the  anus.  Owing  principally  to  a 
well  marked  difference  in  magnitude,  it  is  divided  by  anatomists 
into  the  Small  and  into  the  Large  intestine. 


Of  the  Small  Intestine  * 

The  Small  Intestine  ( Intestinum  Tenue)  commences  at  the  pylorus, 
and  terminates  in  the  right  iliac  region  by  a lateral  aperture  into  the 
large  intestine.  It  is  four-fifths  of  the  length  of  the  whole  canal, 
and  measures  from  twenty-four  to  twenty-eight  feet. 7 When  mo- 
derately distended  its  diameter  is  about  one  inch.  It  retains  from 
one  end  to  the  other  an  uninterrupted  cylindrical  shape,  with  the 
exception  that  if  the  two  ends  be  compared,  the  upper  will  be  found 
larger  than  what  is  stated  as  the  medium  measurement,  and  the 
lower  smaller;  by  which  arrangementit  occurs  that  the  intestine  de- 
creases successively  from  above  downwards;  and,  as  a whole,  is 
slightly  conoidal  or  spindle  shape,  though  this  diminution  is  so 
gradual  that  it  is  not  perceptible  in  any  short  space. 

The  small  Intestine,  like  the  stomach,  consists  of  four  distinct 
coats,  the  peritoneal,  the  muscular,  the  cellular,  and  mucous. 

The  Peritoneal  Coat  is  complete,  and  forms  the  external  surface. 
It  is  continued  afterwards  in  two  laminae  from  the  intestine  to  the 
lumbar  vertebrae,  thereby  constituting  the  Mesentery.  The  two 
laminae,  where  they  depart  from  the  intestine,  are  loosely  connected 
with  each  other,  for  the  purpose  of  allowing  room  for  the  dilatation 
of  the  intestine,  on  the  same  principle  which  is  exemplified  in  regard 
to  the  stomach. 

* Anat.  Atlas,  Figs.  313  to  324,  inclusive. 

f This  is  the  generally  received  opinion  of  anatomists : it  would  appear, 
however,  to  be  applicable  only  when  the  intestine  is  left  attached  to  the  me- 
sentery; for  if  it  be  cut  off  and  straightened,  it  will  measure  thirty-four  feet, 
which,  added  to  eight  feet  of  large  intestine  treated  in  the  same  way,  will 
amount  in  all  to  forty-two  feet.  If  to  the  estimate  of  this  length  we  add  what 
is  lost  by  the  doublings  of  the  mucous  coat,  the  entire  length  of  surface  must 
amount  to  nearly  sixty  feet ; at  least,  in  many  subjects. 


38 


ORGANS  OF  DIGESTION. 


The  Muscular  Coat  is  next  to  the  peritoneal.  Its  fibres  are  pale, 
and  form  a lamina  not  so  thick  as  common  writing  paper.  The 
superficial  ones  are  longitudinal,  not  very  distinct,  and  too  much 
separated  to  form  a perfect  coat:  they  are  most  abundant  on  the 
anterior  semicircumference  or  the  one  most  distant  from  the  Mesen- 
tery. The  others  all  run  in  a circular  direction,  approaching  to  the 
spiral,  and  are  sufficiently  numerous  to  form  a perfect  coat:  none  of 
them  perform  a complete  circuit  of  the  intestine,  but  are  rather 
segments  of  circles.  This  coat  is  united  to  the  peritoneal  by  a thin 
scattered  cellular  substance. 

The  Cellular  Coat  of  the  small  intestine,  ( Tunica  propria)  also 
called  the  Nervous,  like  that  of  the  stomach,  is  only  a lamina  of 
dense  cellular  substance,  which  serves  as  a medium  of  connexion 
between  the  muscular  and  the  mucous  coat:  and  also  conducts  to 
the  latter  the  blood  vessels,  nerves,  and  lacteals.  When  inflated 
and  dried,  it  puts  on  a beautiful  cotton-like  appearance — just  as  the 
corresponding  coat  of  other  parts  of  the  alimentary  canal  does  under 
the  same  treatment. 

In  the  lion  this  membrane  presents  a most  elegant  clear  tendi- 
nous appearance,  and  is  so  strong  that  it  will  bear,  from  the  interior, 
the  pressure  of  a column  of  water  eighteen  feet  high.  The  mus- 
cular and  peritoneal  coats  splitting  open,  while  it  remains  entire. 
Under  this  strong  pressure  of  water  neither  the  lacteals  nor  blood 
vessels  are  filled  with  it,  which  goes  to  prove  that  the  introduction 
of  articles  into  them,  from  the  intestinal  cavity,  is  a vital  and  not  a 
physical  action. 

The  Mucous  Coat  is  the  most  internal,  and  when  it  has  been 
cleaned  by  maceration,  exhibits  an  'opaque  pearly  colour.  It  is 
remarkable  for  having  its  extent  very  considerably  augmented 
beyond  that  of  the  other  coats,  by  being  thrown  into  a great  number 
of  permanent  folds,  or  duplicatures;  which  lie  one  upon  another 
successively,  like  the  shingles  upon  the  roof  of  a bouse.  These 
duplicatures  are  the  Valvulse  Conniventes,  and  are  for  the  most  part 
about  three  lines  in  breadth.  They  are  either  placed  in  the  direc- 
tion of  the  circumference  of  the  intestine,  or  are  very  slightly  ob- 
lique; generally  they  go  all  around,  but  many  of  them  are  segments 
of  circles,  and  by  being  arranged  successively,  their  ends  pass  one 
another,  or  are  connected  by  slight  elevations.  They  are  more 


INTESTINAL  CANAL. 


39 


numerous  and  broad  in  the  upper  than  in  the  lower  half  of  the  in- 
testinum  tenue,  and  are  evidently  intended  to  retard  the  progress 
downwards  of  alimentary  matter,  and  to  increase  the  surface  for 
absorption  and  for  exhalation. 

The  mucous  membrane,  on  the  side  which  it  presents  to  the  cavity 
of  the  intestine,  is  furnished  with  a great  number  of  delicate  cylin- 
drical projections,  resembling  the  down  on  the  skin  of  an  unripe 
peach,  and  called  Villi,* * * §  from  whence  the  term  villous  has  also  been 
applied  to  this  coat.  These  villi  are  to  be  found  in  abundance  every- 
where ; but  in  the  upper  half  of  the  intestinum  tenue  they  are  so 
numerous  as  to  stud  its  whole  surface,  and  to  be  in  contact  with 
each  other.  They  are  from  one-fourth  of,  to  a line  in  length;  and 
some  of  them,  when  examined  with  a microscope,  appear  flattened 
and  fungiform.  According  to  the  estimate  of  Meckel, f where  they 
are  thickest,  every  square  inch  of  intestine  furnishes  about  four 
thousand  of  them,  and  by  extending  this  computation,  with  a proper 
allowance  for  diminished  numbers  below,  their  aggregate  amount  is 
about  one  million 4 

Each  Villus  is  composed  of  an  artery,  a vein,  and  a lacteal  ab- 
sorbent; all  united  by  cellular  substance. § From  the  extreme  vas- 
cularity of  the  mucous  membrane,  the  blood  vessels  readily  receive 
a fine  injection  and  thereby  become  evident,  forming  a very  delicate 
vascular  net- work  in  each  of  the  villi.  It  is  generally  believed,  that 
the  absorbent  opens  on  its  surface,  but  whether  by  one  or  more 
orifices  is  yet  unsettled.  According  to  the  celebrated  Lieberkuhn, 
there  is  commonly  but  one  orifice  at  the  end  of  each  villus,  and  very 
rarely  two:  this  assertion  he  considered  himself  as  having  esta- 
blished by  passing  a current  of  air  through  the  villus  till  it  was  dried, 
and  then  slitting  it  open.  Hewson,  Cruikshank,  and  W.  Hunter, 
on  the  contrary,  are  said  to  have  found  many  more,  amounting  even 
to  twenty,  on  such  villi  as  were  gorged  with  chyle.  The  subject 
has  been  fruitful  in  controversy  to  anatomists,  and  ranks  many  dis- 

* This  is  intended  merely  as  an  expression  of  the  common  and  received 
notion,  my  own  views  are  exhibited  in  the  minute  anatomy  of  this  coat. — 
Sect.  hi. 

f Manuel  d’Anat. 

X Aids  is  probably  much  below  their  real  number;  in  an  observation  at  the 
University  we  have  found  the  villi  on  the  ileum  at  its  lower  part  amounting  to 
six  thousand  four  hundred  to  the  square  inch,  but  as  their  shape  varies  very 
much,  as  we  shall  see ; a rule  cannot  be  derived  from  their  shape. 

§ Anat.  Atlas,  Figs.  310 — 312. 


40 


ORGANS  OF  DIGESTION. 


tinguished  champions  on  each  side ; but  from  the  minuteness  of  the 
parts  under  discussion,  it  is  exposed  to  much  fallacy  and  illusion  ; 
and  is  not  as  yet  fully  settled.  The  more  important  fact,  however, 
is  conceded  by  the  admission  of  all,  that  there  is  a branch  of  the 
absorbent  system  in  every  villus;  and  which  has,  for  its  function, 
the  absorption  of  chyle  from  the  cavity  of  the  intestine. 

A more  recent  observation  has  been  made  by  Professor  Krause,* 
in  the  body  of  a young  man  who  had  been*  hung  after  taking  a full 
meal,  he  found  the  villi  of  the  jejunum  beautifully  filled  with  chyle. 
'Fhe  lacteal  of  each  villosity  arose  by  several  branches,  of  which  some 
terminated  by  a free  extremity,  and  others  by  anastomosis  with  each 
other.  Judging  from  his  plate,  he  does  not  appearto  have  traced  any 
branch  to  the  surface  of  the  villus.  Muller  says,  that  he  himself  had 
never  seen  any  opening  at  the  extremity  of  the  villi.  This  corresponds 
with  my  own  experience,  as  I have,  also,  in  one  case,  had  a fine  op- 
portunity of  seeing  them  distended  with  chyle.  The  villi,  however, 
under  any  circumstances,  cannot  be  considered  as  the  sole  organs 
for  the  absorption  of  chyle,  for  in  many  animals  they  do  not  exist. f 
A more  calm  inquiry  into  this  matter  will,  probably,  bring  us  all  to 
the  conclusion,  that  the  villi  exercise  a tactile  more  than  an  absorb- 
ing power,  which  office  their  strong  analogy  with  the  papillae  of  the 
cutis  vera  strongly  points  out. 

An  abundance  of  Mucous  Glands  is  found  deposited  in  the  cel- 
lular coat  of  the  small  intestine,  between  the  muscular  and  the  vil- 
lous ; their  ducts  open  upon  the  internal  surface  of  the  latter,  in  the 
interstices  of  the  villi,  and  from  their  smallness  require  the  intestine 
to  be  floated  in  water,  and  examined  with  a magnifying  glass,  before 
they  can  be  recognised.  In  order  to  see  the  glands  themselves,  the 
intestine  must  be  cleaned  by  soaking  it  in  water;  it  is  then  to  be  slit 
open  longitudinally,  and  held  between  the  eye  and  the  light,  in 
which  case  the  glands  appear  like  little  points  or  spots  in  the  thick- 
ness of  the  intestine.  They  are  more  abundant  in  the  beginning  of 
the  latter,  decrease  about  its  middle,  and  increase  again  towards  its 
termination.  Their  structure  is  very  simple,  as  they  consist  in  a 
congeries  of  blood  vessels,  terminating  in  short  canals  secreting 
mucus. ij: 

Some  of  these  glands  are  microscopical,  and  are  called  cryptic : 

* Muller’s  Archives,  1837. 

f Muller,  Physiol,  pp.  287,  288. 

\ Soemmering-,  de  Corp.  Hum.  Fabrica. 


INTESTINAL  CANAL. 


41 


they  appear  as  extremely  fine  cul-de-sacs,  or  blind  pouches,  made 
by  inflections  simply  of  the  mucous  coat,  and  are  at  the  rate  of  near 
twenty-five  thousand  to  the  square  inch,  with  a diameter  varying 
from  about  the  fortieth  to  the  twentieth  of  a line.  Other  glands  are 
to  be  found  from  that  size  to  a line  in  diameter,  and  flattened. . They 
are  either  alone  or  in  clusters.  The  solitary  ones  ( Glandules  Soli- 
taries, Brunneri ,)  are  found  principally  about  the  duodenum  and 
the  neighbouring  portion  of  the  small  intestine,  but  also  exist  all  the 
way  down  in  a scattered  manner.  The  others  ( Glandules  Agminatce , 
Peysri ,)  exist  principally  in  the  lower  part  of  the  small  intestine,  and 
are  collected  into  clusters  varying  from  a few  lines  to  three  or  four 
inches  in  length,  but  seldom  more  than  from  eight  to  twelve  lines 
broad.  They  are,  for  the  most  part,  in  elliptical  patches,  which,  in 
a healthy  state,  may  be  recognised  rather  by  a slight  discoloration, 
than  by  the  more  ordinary  means,  and  are  generally  situated  some 
distance  from  the  mesentery.  There  are  about  thirty  of  these  clus- 
ters, of  all  sizes,  in  the  ileum,  and  they  are  placed  nearer  and  nearer 
to  one  another,  in  approaching  the  ileo-colic  junction.  All  of  these 
glands  of  Peyer  are  too  much  flattened  to  project  sensibly  into  the 
cavity  of  the  intestine,  and,  when  they  do,  there  is  reason  to  believe 
that  they  are  in  a diseased  state,  at  least  in  the  adult.  For  the  most 
part,  in  children,  the  glands  of  Brunner  may  be  seen  without  diffi- 
culty, in  the  whole  length  of  the  small  intestine,  and  in  adults  some 
are  found  to  project  like  little  hemispherical  grains  at  wide  intervals 
apart  into  the  duodenum. 

The  mucous  coat  of  the  small  intestine  is  every  where  extremely 
vascular. 

The  Small  Intestine,  though  an  uninterrupted  tube  from  one  end 
to  the  other,  is  divided  by  anatomists  into  Duodenum,  Jejunum,  and 
Ileum.  There  is  some  reason  for  the  first  name,  but  the  two  latter 
may  be  very  conveniently  blended,  as  has  been  done  by  some,  under 
the  term  Mesenteric  Portion  of  the  intestinal  canal. 

The  Duodenum,  named  from  its  being  about  twelve  inches,  or 
twelve  fingers’  breadth  in  length,  is  nearest  to  the  stomach,  and  is 
the  commencement  of  the  canal.  It  is  considerably  larger  than 
either  of  the  others,  and  is,  moreover,  susceptible  of  great  dilatation, 
whence  it  has  also  been  called  Ventriculus  Succenturiatus.  Its  di- 
rection is  much  varied  ; beginning  at  the  pylorus,  it  first  of  all  passes 

Vol.  II.— 5 


42 


ORGANS  OF  DIGESTION. 


upwards  and  to  the  right  side  till  it  reaches  the  neck  of  the  gall- 
bladder ; it  then  turns  downwards,  so  as  to  form  a right  angle  with 
itself,  and  descends  in  front  of  the  right  kidney  to  the  third  lumbar 
vertebra,  being  there  placed  behind  the  superior  lamina  of  the  trans- 
verse mesocolon.  It  then  forms  a round  elbow,  crosses  the  spine 
obliquely,  under  the  junction  of  the  mesentery  and  mesocolon,  in 
ascending  from  right  to  left ; and  making  its  appearance  to  the  left 
of  the  second  lumbar  vertebra,  is  there  continued  into  the  mesenteric 
portion  of  intestine. 

The  beginning  of  the  duodenum  is  moveable,  and  has  a peritoneal 
coat  continued  from  the  lesser  omentum  ; the  descending  and  the 
transverse  portions  have  no  proper  peritoneal  coat,  but  are  only 
loosely  fixed  between  the  laminae  of  the  mesocolon  ; the  termination 
of  the  duodenum  is  both  moveable  and  has  a peritoneal  covering, 
from  being  at  the  commencement  of  the  mesentery. 

From  the  course  assigned  to  the  duodenum,  it  is  evident  that  it 
forms  the  segment  of  a circle,  the  concavity  of  which  looks  to  the 
left  side.  This  concavity  is  occupied  by  the  head  of  the  pancreas. 
The  transverse  portion  crosses  the  spine  below  the  pancreas,  and  is 
separated  from  it  by  the  superior  mesenteric  artery  and  by  the  vena 
portarum : behind  it  are  the  crura  of  the  diaphragm,  the  ascending 
cava,  and  the  aorta. 

The  organization  of  the  duodenum  is  the  same  with  that  of  other 
portions  of  the  intestinum  tenue.  Its  peculiarities  consist  only 
in  a partial  deficiency  of  peritoneal  coat,  and  in  its  augmented 
size.  Its  internal  or  mucous  coat  is  very  much  tinged  with  bile, 
abounds  invalvulae  conniventes,  especially  in  its  inferior  three-fourths, 
and  about  four  inches  from  the  pylorus  is  marked  by  a small  tubercle 
or  elevation  indicative  of  the  common  orifice  of  the  biliary  and  pan- 
creatic ducts.  The  Glands  of  Brunn,  commonly  called  of  Brunner, 
are  very  conspicuous  in  this  intestine  on  raising  its  mucous  coat, 
and  are  so  numerous  near  the  pyloric  orifice,  as  to  form  with  some  a 
perfect  layer,  and  to  give  it  a granulated  appearance  for  two  inches 
or  more.  These  glands  originally  called  the  Secondary  Pancreas 
by  Brunn,  are  also  considered  by  Mr.  Cruveilhier  and  Boehm  to  be 
pancreatic  in  their  structure.  This  idea  was  first  inculcated  by 
their  discoverer,*  who  considered  them  to  secrete  a peculiar  liquor, 

* .1.  Conrad,  A.  Brunn,  Gland.  Duodeni  Seu  Pancreat.  Secund.  Descriptio 
Anat.,  for  which  treatise  in  full  see  Mangetus,  Theatr.  Anat.  t.  i.  p.  276. 
Geneva,  1716.  The  other  glands  of  Brunner  found  all  the  way  down  the  small 


INTESTINAL  CANAL. 


43 


but  thought  that  the  action  of  the  pancreas  if  it  were  exterminated 
would  easily  pass  to  them,*  hence  his  appellation  to  them  of  Pancreas 
Secundarius. 

The  Jejunum  and  Ileum  form  the  remaining  length  of  the  small 
intestine,  and  have  no  external  marks  of  difference  from  each  other. 
They  are  strung  along  the  mesentery,  and,  in  consequence  of  their 
great  length,  are  thrown  into  folds  or  convolutions,  which  give  to 
them  a complicated  appearance.  There  is,  however,  no  difficulty  in 
tracing  them  regularly  from  one  end  to  the  other.  They  occupy  the 
umbilical,  the  hypogastric,  and  a part  of  the  iliac  regions,  and  are 
surrounded  by  the  circuit  of  the  colon.  The  upper  two-fifths  is  the 
jejunum,  and  the  lower  three-fifths,  the  ileum.  This  distinction, 
originally  introduced  by  Galen, f from  a supposition  that  the  jeju- 
num was  more  frequently  found  empty  than  any  other  intestine,  has 
no  rigid  anatomical  support.  The  only  difference  between  the  two 
is,  that  the  valvulae  conniventes,  existing  as  they  do  in  the  whole 
length  of  the  jejunum,  become  less  abundant  at  the  upper  part  of 
the  ileum,  and  finally  disappear  entirely  towards  its  lower  extremity. 
They  decrease  indeed  very  sensibly  at  the  lower  part  of  the  jeju- 
num, and  sometimes  there  are  none  at  all  in  the  ileum.  In  an  ob- 
servation made  carefully  on  this  matter  by  detaching  the  intestine 
from  the  mesentery — inverting  it  and  then  measuring,  I found  the 
valvulae  conniventes  to  cease  as  near  as  may  be,  in  the  middle  of 
the  length  of  the  mesenteric  portion  of  the  intestinal  canal.  The 
above  distinction  into  jejunum  and  ileum  has  been  rejected  by  the 
most  approved  modern  authorities,  such  as  Haller,  Soemmering,  and 
Meckel. 

It  sometimes  happens,  that  the  intestinum  tenue  has  one  or  more 
blind  pouches  like  caeca  appended  to  its  sides  and  opening  into  its 
cavity. 

The  small  intestine  is  supplied  with  blood  from  the  superior  me- 
senteric artery.  Its  nerves  come  from  the  sympathetic. 

The  Mesentery  ( Mesenterium ) is  a process  of  peritoneum  which 
serves,  as  mentioned,  to  connect  the  intestinum  tenue  to  the  poste- 
rior parietes  of  the  abdomen,  and  extends  its  connexions  from  the 
left  side  of  the  second  lumbar  vertebra  to  the  right  iliac  fossa.  This 
attachment,  called  the  root,  is  about  six  inches  in  length  ; whereas,. 

intestine,  are  evidently  different  from  these  in  being  more  spherical,  always 
solitary,  and  small  in  comparison. 

* Id.  p.  291. 


f Portal,  Anat.  Med. 


44 


ORGANS  OF  DIGESTION. 


its  lower  circumference,  which  encloses  the  small  intestine  by  giving 
it  a peritoneal  coat,  is,  of  course,  the  whole  length  of  the  bowel, 
(duodenum  excepted,)  and,  consequently,  from  twenty-three  to 
twenty-seven  feet  in  length.  This  expansion  becomes  intelligible 
the  moment  that  the  arrangement  of  the  part  is  inspected,  and  is 
somewhat  after  the  manner  of  a ruffle,  except  that  it  is  not  puckered 
at  the  root. 

The  two  laminae  of  peritoneum  which  form  the  mesentery,  con- 
tain between  them  the  superior  mesenteric  artery,  and  the  correspond- 
ing portion  of  the  superior  mesenteric  vein  ; an  abundance  of  lym- 
phatic or  lacteal  glands  and  vessels ; ramifications  from  the  solar 
plexus  of  the  sympathetic  nerves ; and  a considerable  quantity  of 
cellular  and  of  adipose  tissue.  The  superior  lamina  is  continued 
directly  into  the  mesocolon,  and  at  the  place  of  junction  the  trans- 
verse part  of  the  duodenum  is  very  perceptible  beneath.  The  lower 
lamina  descends  along  the  posterior  parietes  of  the  abdomen,  con- 
cealing the  large  blood  vessels  there,  and  the  ureters. 


Of  the  Large  Intestine* 

The  Large  Intestine  ( Intestinum  Crassum ) receives  the  effete 
matter  from  the  small,  and  is  supposed  also  to  make  some  peculiar 
secretion  of  faecal  matter  from  its  internal  surface.  It  exceeds  much 
in  its  diameter  the  small  intestine,  and  differs  also  from  it  in  not 
being  by  any  means  so  nearly  cylindrical.  It  commences  at  the  in- 
ferior end  of  the  small  intestine,  and  terminates  at  the  anus,  de- 
scribing in  this  course,  as  mentioned,  a circle  which  surrounds  two- 
thirds  of  the  abdomen,  and  embraces  the  intestinum  tenue.  Like 
the  latter,  though  only  a continuous  tube,  it  is  divided  into  three 
parts  ; the  commencement  of  it,  which  is  below  the  insertion  of  the 
ileum,  and  about  two  inches  in  length,  is  the  Coecum,  or  Caput  Coli ; 
the  remaining  portion,  which  occupies  almost  its  whole  length,  is 
ealled  the  Colon,  until  it  reaches  the  brim  of  the  pelvis,  when  the 
name  is  converted  into  Rectum. 

The  Mesocolon  is  a reflection  or  duplication  of  peritoneum,  that 
fixes  the  large  intestine  to  the  posterior  parietes  of  the  abdomen. 

Anat.  Atlas,  Figs.  325  to  331,  inclusive. 


INTESTINAL  CANAL. 


45 


This  duplicating  is  not  of  a breadth  so  uniform  as  the  mesentery, 
but  allows  to  the  middle  of  the  large  intestine  very  considerable 
motion,  up  and  down,  according  to  the  distention  of  the  stomach, 
while  the  lateral  portions  are  very  much  confined.  For  instance,  in 
the  right  iliac  fossa  the  mesocolon  is  so  short  that  the  posterior  sur- 
face of  the  gut  is  in  contact  with  the  iliac  fascia,  and  adheres  to  it  by 
loose  cellular  substance  ; and  in  the  right  and  left  lumbar  regions 
tire  bowel  is  immoveably  fixed  in  front  of  the  kidneys  near  their 
outer  margin  : but  in  the  space  between  these  two  points,  that  is  to 
say,  where  the  bowel  traverses  the  hypochondriac  and  the  epigastric 
or  umbilical  region,  the  peritoneal  attachment,  here  called,  from  its 
situation,  the  transverse  mesocolon,  is  so  long  and  so  loose  that  it 
forms  a complete  and  moveable  septum  between  the  small  intestine 
and  the  stomach.  In  the  left  iliac  region,  again,  the  large  intestine, 
after  having  been  bound  down  to  the  left  lumbar,  is  suddenly 
loosened  by  an  increased  breadth  of  the  mesocolon,  which  permits 
it  to  form  a large  convolution,  called  its  sigmoid  flexure.  The  me- 
socolon is  then  continued  into  the  pelvis  in  front  of  the  sacrum,  first 
of  all  a little  to  the  left  of  the  middle  line  of  the  latter,  and,  as  it  de- 
scends it  gets  directly  in  front  of  the  middle  line.  The  portion  of  it 
in  the  pelvis  is  called  mesorectum,  from  the  gut  which  it  serves  to 
attach. 

The  composition  of  the  mesocolon  is  precisely  the  same  with  that 
of  the  mesentery,  though  it  be  not  so  thick : it,  therefore,  consists 
in  two  laminae  of  peritoneum,  which  contain  between  them  some 
adipose  and  cellular  matter,  along  with  the  arteries,  the  veins,  the 
nerves,  and  the  absorbent  vessels  and  glands  belonging  to  the  large- 
intestine. 

When  the  large  intestine  is  inflated,  it  is  rendered  very  obvious 
that  it  decreases  in  size  from  its  commencement  to  the  lower  part  of 
the  sigmoid  flexure,  it  then  increases  again  in  size  just  above  the 
anus.  Its  surface  is  arranged  into  three  series  or  longitudinal  rows 
of  projections,  separated  by  transverse  depressions,  the  whole  cor- 
responding with  an  internal  cellular  arrangement,  by  the  latter  sur- 
face being  the  reverse  of  the  former. 

Its  coats,  like  the  small  intestine,  are  four  in  number;  the  perito- 
neal, the  muscular,  the  cellular,  and  the  mucous. 

The  Peritoneal  Coat  prevails  in  its  whole  extent,  with  the  ex- 

5* 


46 


ORGANS  OF  DIGESTION. 


ception  of  the  lower  part  of  the  rectum : on  the  ascending  and  the 
descending  portions  of  the  colon,  however,  where  the  latter  comes 
in  contact  with  the  parietes  of  the  abdomen,  the  peritoneum  does 
not  invest  it  entirely ; but  the  transverse  portion  or  the  arch,  as  it 
is  called,  and  the  sigmoid  flexure,  are  completely  surrounded. 

The  surface  of  this  intestine  is  studded  with  small  projections  of 
various  lengths,  called  Appendices  Epiploicae,  which  are  small  du- 
plicatures  of  the  peritoneal  coat  containing  fat. 

The  Muscular  Coat  is  thin,  and  like  that  of  the  small  intestine, 
consists  of  two  orders  of  fibres,  the  longitudinal,  and  the  transverse 
or  circular. 

The  longitudinal  fibres  have  the  peculiarity  of  being  collected 
into  three  equidistant,  flattened  fasciculi  or  bands,  of  about  half  an 
inch  in  breadth,  which  begin  by  a common  point  at  the  extremity 
of  the  cceeum,  and  extend  to  the  upper  end  of  the  rectum.  One 
of  them  is  along  the  line  of  junction  with  the  mesocolon,  another 
anterior,  and  the  third  inferior.  These  fibres,  being  shorter  than 
the  other  coats  of  the  gut,  have  the  effect  of  puckering  them  into 
the  internal  cellular  condition  alluded  to  ; for,,  when  they  are  cut 
through,  the  intestine  is  much  elongated,  and  its  cells  disappear. 
It  occasionally  happens  that  the  longitudinal  fibres,  instead  of  being 
confined  to  the  bands  mentioned,  exist  in  considerable  quantity  over 
the  intermediate  spaces;  in  this  case  the  cellular  arrangement  is  not 
so  complete,  and  in  some  instances  is  entirely  dispensed  with  ; of 
the  latter,  an  example  is  in  the  Anatomical  Museum. 

The  circular  muscular  fibres  form  a thin  semi-transparent  lamina 
beneath  the  last,  and  do  not  present  any  peculiarity  of  interest,  they 
make  a thicker  layer  than  exists  in  the  small  intestine. 

The  Cellular  Coat,  or  Tunica  Propria,  is  a thin  lamina  of  dense 
cellular  substance,  serving  to  connect  the  muscular  with  the  mucous 
coat,  and  to  conduct  the  blood  vessels  and  nerves  to  their  termina- 
tions on  the  latter. 

The  Mucous  Coat  lines  smoothly  the  internal  face  of  the  cellular, 
and  has  no  doublings  or  folds,  exclusively  in  it,  like  the  valvulce 
conniventes  of  the  small  intestine.*  The  transverse  projections 

♦This  may  be  considered  as  the  general  rule:  if  the  gut  be  examined, 
however,  in  its  whole  length,  here  and  there  narrow  folds  may  be  found  in 
some  subjects. 


INTESTINAL  CANAL. 


47 


which  it  makes  between  the  longitudinal  bands,  into  the  cavity  of 
the  gut,  and  which  separate  the  cells  of  the  large  intestine  from  each 
other,  are  not  mere  duplicatures  of  it  alone,  but  are  also  constituted 
by  the  other  coats. 

Near  its  commencement  this  coat  has  the  fungous  appearance  of 
the  stomach,  but  about  the  sigmoid  flexure  it  has  a plain,  smooth, 
and,  to  a degree,  a polished  surface.  It  has  but  few  villi,  such  as 
exist  in  the  small  intestine ; indeed,  some  anatomists  deny  that  it 
has  any,  and  I have  not  myself  seen  them  after  repeated  and  care- 
ful examinations.  Its  muciparous  glands  are  numerous,  and,  when 
somewhat  enlarged,  project;  they  are  very  conspicuous  about  the 
sigmoid  flexure,  and  in  the  rectum.  The  enteric  follicles  exist  in  this 
large  intestine  strikingly,  as  they  do  in  the  mucous  coat  of  the  sto- 
mach and  small  intestine.  Their  number,  on  an  average,  is  about 
twenty  thousand  to  the  square  inch,  with  a diameter  varying  from 
about  the  fortieth  to  the  twentieth  of  a line.  When  examined  with 
a microscope  they  make  this  mucous  membrane,  owing  to  its  smooth- 
ness, look  like  a riddle.  The  lacteals  are  not  abundant. 

The  mucous  coat  of  the  large  intestine  is  very  vascular,  but  not 
so  much  so  as  that  of  the  small  intestine. 

Each  division  of  the  large  intestine  has  some  peculiarities  of 
structure  and  connexions ; which  may  now  be  attended  to. 

The  Coecum,  or  Caput  Coli,  is  generally  from  an  inch  and  a 
half  to  two  inches  long,  has  a rounded  termination  below  and 
somewhat  to  the  left,  from  which  proceeds  an  intestinal  process, 
the  Appendicula  Vermiformis.  The  latter  is  from  three  to  four 
inches  long,  is  cylindrical,  has  a diameter  of  two  or  three  lines,  and 
consists  of  the  same  number  of  coats,  having  the  same  structure 
with  other  portions  of  the  intestinal  canal ; its  base  is  the  place  from 
which  the  three  longitudinal  bands  start.  It  is  attached  to  a narrow 
duplicature  of  peritoneum,  a process  of  the  mesentery,  which  per- 
mits it  to  float  loosely  in  the  abdomen.  It  seldom  contains  faeces, 
but  is  kept  distended  by  flatus. 

The  ccecum,  as  mentioned,  is,  for  the  most  part,  confined  to  the 
right  iliac  fossa,  but  we  very  frequently  see  it  with  a length  of  peri- 
toneal attachment  permitting  it  to  descend  for  a short  distance  into 
the  lesser  pelvis. 

The  Ileo-colic  Valve  ( Valvula  Bauhini ) is  formed  at  the  junction 
of  the  ileum  with  the  caput  coli.  This  valve,  destined  to  prevent 


48 


ORGANS  OF  DIGESTION. 


the  return  of  fa1  cal  matter  from  the  large  into  the  small  intestine,  con- 
sists in  a transverse  elliptical  opening,  or  slit,  whose  two  lips  become 
approximated  in  the  distentions  of  the  colon.  The  ileum  runs  into 
the  left  wall  of  the  large  intestine,  and  continues  its  cellular  and 
mucous  coats  into  the  corresponding  coats  of  the  latter.  The  cir- 
cular fibres  of  the  large  intestine  separate  to  a certain  degree  to 
permit  this  introduction,  but  their  farther  separation  is  restrained  at 
each  commissure  or  corner  of  the  lips,  by  a blending  of  the  structure, 
aided  by  a few  ligamentous  fibres,  designated  as  the  retinacula  of 
Bauhin  or  of  Morgagni;  which,  however,  are  frequently  not  very 
distinct.  This  separation  is  also  restrained  by  the  two  longitudinal 
bands  between  which  the  lips  are  placed,  one  of  which  bands  is  at 
the  posterior  commissure,  and  the  other  only  a short  distance  from 
the  anterior.  The  lips  themselves,  formed  principally  by  the  mucous 
membrane,  approach  one  another  after  the  manner  of  the  ship  dock 
or  canal  gate  ; the  superior  is  somewhat  broader  than  the  inferior. 
Their  power,  as  well  as  their  existence,  depends  entirely  on  the 
tension  which  is  kept  up  by  the  natural  connexions  of  the  parts ; for 
a very  slight  dissection  causes  them  to  become  almost  effaced,  and 
instead  of  forming  an  elliptical  transverse  opening,  to  be  converted 
into  a round  patulous  one. 

The  Colon,  properly  speaking,  has  some  regional  distinctions 
which  are  serviceable  to  accurate  description.  The  right  lumbar 
colon,  which  is  bordered  in  front  by  the  small  intestine,  and  behind, 
by  the  right  kidney,  extends  from  the  ileo-colic  valve,  to  the  margin 
of  the  false  ribs  of  the  corresponding  side.  The  transverse  colon, 
bordered  above  by  the  stomach,  and  below  by  the  small  intestine, 
goes  from  one  hypochondriac  region  to  the  other.  It  is  generally 
found  more  distended  than  the  other  portions.  The  left  lumbar 
colon  descends  from  the  hypochondriac  region  of  the  left  side  to  the 
sigmoid  flexure,  being  bordered  behind  and  to  its  right  margin  by 
the  left  kidney,  and  in  front  by  the  small  intestine.  The  sigmoid 
flexure,  placed  in  the  left  iliac  fossa,  forms  a convolution,  but  is  very 
indifferently  described  by  the  term  applied  to  it.  It  is  occasionally 
very  long  and  loose,  and  terminates  at  the  left  sacro-iliac  symphysis. 
It  is  not  unfrequently  found  destitute  of  the  partitions  which  prevail 
in  other  parts. 


The  Rectum  begins  at  the  left  sacro-iliac  symphysis,  and  passes 


INTESTINAL  CANAL. 


49 


obliquely  downwards  to  the  centre  of  the  sacrum,  thence  in  front  of 
the  middle  line  of  the  sacrum,  and  of  the  coccyx,  to  terminate  at  the 
point  of  the  latter.  It  is  not  regularly  cylindrical,  but,  just  above 
the  anus,  is  dilated  into  a wide  pouch,  flattened  from  before  back- 
wards by.  the  pressure  of  the  bladder,  and  very  distinguishable  upon 
the  introduction  of  the  finger,  for  it  is  but  seldom  in  a contracted 
state.  It,  of  course,  has  a flexure  by  adapting  itself  to  the  concavity 
of  the  sacrum,  and  is  bounded  in  front  by  the  bladder,  the  prostate 
gland,  and  the  vesiculae  seminales  of  the  male ; and  by  the  vagina 
and  the  uterus  of  the  female. 

The  peritoneum  covers  only  the  superior  two-thirds  of  the  rec- 
tum, and  attaches  it  by  the  short  duplicature,  called  the  mesorectum, 
to  the  front  of  the  sacrum.  A small  pouch,  passing  down  between 
the  vesiculse  seminales  almost  to  the  base  of  the  prostate,  is  formed, 
as  mentioned  previously,  by  the  peritoneum  in  its  course  from  the 
rectum  to  the  bladder. 

The  muscular  coat  of  the  rectum  has  a thickness  and  redness  sur- 
passing much  that  of  any  other  intestine,  and  is  divided  very  clearly 
into  two  laminae,  the  external  of  which  consists  in  longitudinal  and 
the  internal  in  circular  fibres.  The  external  forms  in  itself  a com- 
plete coat  continuous  with  the  longitudinal  bands  of  the  colon,  but 
is  much  increased  in  thickness  over  them  by  additional  fibres.  The 
circular  fibres  also  form  a complete  coat,  and,  just  below  the  pouch 
of  the  rectum,  are  multiplied  so  much  for  eight  or  ten  lines  as  to  be 
a perfect  internal  sphincter  muscle,  bearing  a strong  analogy  with 
the  pyloric  muscle  of  the  stomach.*  At  the  anus,  an  arrangement 
of  the  muscular  coat  prevails,  which  is  not  sufficiently  attended  to 
by  anatomists.  The  longitudinal  fibres,  having  got  to  the  lower 
margin  of  the  internal  sphincter,  turn  under  this  margin  between  it 
and  the  external  sphincter,  and  then  ascend  upwards  for  an  inch  or 
two  in  contact  wflth  the  mucous  coat,  or  rather  its  cellular  substra- 

* It  has  been  recently  asserted  that  there  is  also  a sphincter  muscle  four 
inches  above  the  anus,  half  an  inch  wide  in  front,  and  one  inch  wide  behind, 
from  whence  according  to  Mr.  Velpeau  the  fibres  go  in  crossing  one  another  to 
fix  themselves  to  the  front  of  the  sacrum.  Mr.  Lisfranc  appears  to  have  first 
announced  it  and  Mr.  Nelaton  to  have  described  it.  Malgaigne,  Anat.  Chi- 
rurg.  vol.  2d,  p,  343.  Paris,  1838.  I doubt  very  much  the  uniformity  of  the 
distinct  existence  of  such  a muscle,  not  having  been  able  to  find  it  in  the  dis- 
sections which  1 have  instituted  for  the  purpose,  unless  a portion  of  the  ordi- 
nary circular  fibres  should  have  been  selected  for  that  designation,  in  which 
case  several  others  may  be  said  also  to  exist. 


50 


ORGANS  OF  DIGESTION. 


turn,  into  which  they  are  finally  inserted  by  fasciculi  which  form  the 
base  of  the  columns  of  the  rectum ; many  of  the  fibres,  however, 
terminate  also  between  the  fasciculi  of  the  circular  fibres.  This 
connexion  must  have  obviously  much  influence  in  the  protrusions 
of  the  mucous  coat,  which  take  place  in  hemorrhoids  and  in  pro- 
lapsus ani. 

The  mucous  coat  of  the  rectum  is  thick,  red,  and  fungous,  and 
abounds  in  mucous  lacunse  and  glands.  It  is  smoothly  laid  above, 
but  below  it  is  thrown  into  superficial  longitudinal  folds  called 
columns.  At  the  lower  ends  of  the  wrinkles,  between  the  columns, 
are  small  pouches  of  from  two  to  four  lines  in  depth,  the  orifices 
of  which  point  upwards;  they  are  occasionally  the  seat  of  disease, 
and  produce,  when  enlarged,  a painful  itching.  An  original  obser- 
vation of  Dr.  Physick,  on  the  nature  of  this  affection,  and  the  remedy 
for  which  consists  in  slitting  them  open  or  removing  them,  induced 
me  to  look  for  the  ordinary  natural  structure,  which  I have  ascer- 
tained to  be  as  now  described.*  The  radiated  wrinkling  of  the 
anus  is  from  the  influence  of  the  external  sphincter  ani  muscle. 

In  some  subjects,  large  cells  are  formed  in  the  cavity  of  the  rectum 
by  transverse  doublings  of  the  mucous  coat  only,  resembling  the 
valvulse  conniventes  of  the  small  intestine;  this,  however,  is  not 
the  most  frequent  arrangement,  though  deserving  of  notice.  It 
takes  place  under  the  following  mechanism.  About  a finger’s 
length  from  the  anus  there  is  a puckering  of  the  gut,  or  deep  wrink- 
ling, such  as  occurs  in  the  colon,  and  it  arises  from  a similar  cause, 
that  is,  an  abbreviation  of  the  longitudinal  layer  of  fibres  of  the  gut : 
this  abbreviation  is  not  wholly  circular,  but  occupies  the  semi-cir- 
cumference of  the  gut  on  one  side,  and  then  a little  higher  up,  the 
semi-circumference  of  the  other  side.  This  shortening  of  the  gut 
brings  the  fasciculi  of  its  circular  muscular  fibres  more  together, 
and,  therefore,  accumulates  them  into  a greater  thickness.  At  a 
corresponding  part  on  each  side  of  the  gut  in  its  interior,  exists  a 
transverse  doubling  of  the  mucous  coat  forming  the  valvula  con- 

* See  an  interesting  paper  on  Fistula  in  ano,  by  M.  Ribes,  in  Mem.  de  la 
Societe  D’Emulation,  vol.  9,  1826;  where  the  influence  of  this  structure  is 
alluded  to. — Also,  an  elaborate  and  excellent  article  by  Dr.  Reynell  Coates,  in 
the  Cyclopaedia  of  Pract.  Med.  and  Surgery,  Philada.  1835,  under  the  term  Anus. 
It  appears  that  Glisson  and  Ruysch  first  described  them  as  valves.  The  ac- 
curate Winslow  (Douglas’  Translation  vol.  ii.  p.  149,  anno.,  1749,)  was  also 
acquainted  with  this  structure. 


INTESTINAL  CANAL. 


51 


nivens  alluded  to.  The  result  of  this  arrangement  is  a semi-circular 
valve  on  each  side,  one  above  the  other,  the  margins,  or  diameters 
of  which  pass  each  other  in  the  empty  and  contracted  state  of  the 
rectum,  but  touching  at  the  same  time,  and  they  present  an  addi- 
tional barrier  to  the  involuntary  evacuation  of  fseces.* 

Most  subjects,  however,  have  the  mucous  coat  without  these 
valves,  and  merely  in  superficial  wrinkles  of  various  directions. 

The  large  intestine  is  supplied  with  blood  from  a part  of  the 
superior  mesenteric  artery,  from  the  whole  of  the  inferior  mesenteric, 
and  from  the  internal  pudic.  Its  veins  empty  into  the  vena  portarum, 
its  nerves  are  derived  from  the  solar  and  the  hypogastric  plexus  of 
the  sympathetic. 


SECT.  III. — ON  THE  MINUTE  ANATOMY  OF  THE  MUCOUS  COAT 
OF  THE  ALIMENTARY  CANAL,  f 

In  the  preceding  account  of  the  mucous  coat  of  the  stomach  and 
bowels,  I have  admitted  the  most  generally  received  opinions  as 
it  is  in  every  way  proper  for  medical  men  to  be  aware  of  them. 
Having  been,  however,  much  occupied,  a few  years  ago,  in  ascer- 
taining the  pathology  of  Asiatic];  cholera  by  dissections,  the  obser- 
vations which  I then  made  upon  the  healthy  and  diseased  structure, 
have  induced  me  to  modify  very  much  my  former  views,  as  will  be 
seen  in  the  following  pages;  the  subject  has  since  then  been  taken 
up  largely  by  the  anatomists  of  Europe,  with  nearly  similar  results. 

The  mucous  coat  of  the  alimentary  canal,  in  a healthy  state, 
and  successfully  injected,  appears  to  consist  almost  entirely  of  a 
cribriform  intertexture  of  veins.  These  veins  being  commonly 

* It  has  latterly  been  advanced  by  Mr.  O’Beirne,  that  in  a natural  state  the 
rectum  is  empty,  and  that  the  accumulation  of  faeces  preparatory  to  a stool 
occurs  in  the  sigmoid  flexure  of  the  colon,  where  they  are  retained  by  a con- 
traction of  the  upper  end  of  the  rectum.  The  principal  ground  of  this  opinion 
is,  that  fcecal  matter  is  rarely  met  with  in  the  rectum.  The  observation  is  so 
contradictory  to  my  experience  in  the  dissecting  room  and  on  patients,  that  I 
cannot  but  reject  it,  though  it  appears  to  be  obtaining  some  currency,  or  at  least 
is  quoted  respectfully.  Journal  Hebd.  1833,  vol.  xiii.  p.  126.  Malgaigne, 
Anat.  Chir.  vol.  2d,  341. 

j"  Anat.  Atlas,  Figs.  332  to  337,  inclusive,  the  preparations  by  Dr.  Horner 
represented  by  these  figures  are  in  the  Anat.  Museum. 

X Arner.  Journ.  Med.  Sciences,  Vol.  xvi.  May,  1835. 


52 


ORGANS  OF  DIGESTION. 


empty  at  death  present  themselves  then  as  a soft  spongy  structure, 
which  gives  rise  to  the  ordinary  description  of  its  sensible  condi- 
tion as  a velvety  layer.  The  most  minute  injection  of  the  arteries 
scarcely  makes  itself  visible  among  these  veins,  when  they  are  pro. 
perly  injected  also;  a straggling  branch  only  here  and  there  exhi- 
biting itself.  The  arborescence  of  the  arteries  is  confined  to  a 
level  beneath  the  venous  intertexture,  and  is  there  developed  to  an 
extreme  degree  of  minuteness,  being  intermixed  with  correspond- 
ing venous  ramuscles,  generally  larger  and  more  numerous  than 
the  arteries  themselves.  This  arrangement  seems  to  occur  in  that 
surface  of  the  cellular  coat,  which  makes  the  base  or  ground  of  the 
mucous.  The  fine  venous  trunks  of  this  deeper  layer  have  their 
originating  extremities  directed  vertically  towards  the  cavity  of 
the  gut,  and  by  that  means  receive  the  blood  of  the  first  venous 
intertexture  or  layer,  as  the  petrous  sinuses  join  the  cavernous,  or 
the  veins  of  the  penis  arise  from  its  spongy  structure.  The  meshes 
of  the  first  venous  intertexture  are  exceedingly  minute,  and  vary 
in  a characteristic  manner  in  the  stomach,*  small  intestine,  and 
large.  This  intertexture  is  very  different  in  its  looks  from  a com- 
mon vascular  anastomosis,  and  produces  in  the  colon  an  appear- 
ance resembling  a plate  of  metal  pierced  with  round  holes  closely 
bordering  upon  each  other ; these  holes  constitute,  in  fact,  the  fol- 
licles of  Lieberkuhn,  so  called  from  their  discoverer  ;f  these  folli- 
cles are  gaping  orifices,  the  edges  of  which  are  rounded  off’,  and 
their  depth  is  that  of  the  thickness  of  the  venous  anastomosis ; being 
bounded  below  by  the  arterio-venous  layer , just  alluded  to,  and  by 
the  cellular  coat  of  the  part.  Nothing  short  of  an  entirely  success- 
ful injection  will  exhibit  this  venous  anastomosis  as  described  ; and 
it  may  be  seen  either  by  injecting  a vein,  or  an  artery  provided 
the  injection  passes  from  the  arteries,  into  the  veins,  but  the  latter 
process  is  the  least  desirable,  because  we  lose  the  benefit  of  a dis- 
tinction of  colour  between  the  two  sets  of  vessels.^ 

* See  fig.  332  to  335  inclusive. 

f De  fabrica  et  actione  Villor.  intest.  ten.  Leyd.,  1745. 

The  observations  more  recently  of  Dr.  Gaddi  of  Modena,  have  resulted 
in  witnessing  a similar  indisposition  of  the  arteries  to  ramify  in  the  mucous 
coat,  and  the  almost  exclusive  prevalence  of  the  venous  vessels  there.  He 
has  some  views  beside  of  a peculiar  nature,  such  as  that  the  extremities  of  the 
veins  begin  by  open  mouths  on  the  cavity  of  the  intestine,  then  unite  to  form 
a hollow  sphere  situated  in  the  submucous  tissue,  and  that  the  terminating 
ends  of  the  arteries  discharge  into  these  spheres  or  vesicles.  Brit.  & For. 
Med.  Rev.  Oct.,  1841,  p.  530. 


ANATOMY  OF  THE  MUCOUS  COAT. 


5D 


Ordinary  inodes  of  examination  give  no  evidence  of  the  existence 
m the  alimentary  canal,  from  the  cardiac  orifice  of  the  stomach 
to  near  the  anus,  of  an  epidermis  or  epithelium;  on  the  contrary, 
they  rather  lead  to  a belief  of  its  being  absent,  in  consequence  of  the 
softness,  tenuity,  and  transparency  of  the  mucous  membrane  ; but 
that  it  is  really  present,  may  be  proved  by  the  following  process : — 
Tear  off’  the  peritoneal  coat  from  a piece  of  small  intestine — invert 
the  part  and  inflate  it  to  an  emphysematous  condition;  the  epithe- 
lium will  then  be  raised  as  a very  thin  pellicle,  and  may  be  dried 
in  that  state  ; but  as  this  pellicle  retains  the  air,  we  hence  infer  that 
it  lines  the  follicles,  and  is  uninterrupted  by  any  perforations.  This 
epithelium,  if  the  part  be  previously  injected  perfectly,  shows  dots 
of  injecting  matter  like  those  left  in  the  rete  mucosum  upon  a mi- 
nute injection  of  the  skin  ; but  no  arborescence  of  vessels  if  it  be 
raised  up  from  the  veins,  by  the  inflation  stated.  In  so  doing  the 
villi  disappear,  are  in  fact  unfolded. 

In  addition  to  the  above  proof,  the  microscope  in  the  hands  of 
numerous  modern  observers  now  shows,  according  to  the  original 
opinion  of  Lieberkuhn,  the  existence  of  an  epithelium  over  the 
whole  alimentary  canal,  and  which  is  fbrmed  of  minute  soft  scales. 


A 


Fig.  23. 


Cylinders  of  the  intestinal  epithelium,  after  Dr.  Henle : — a.  Cylinders 
from  the  cardiac  region  of  the  human  stomach;  b.  the  same  from  the  jejunum, 
c.  cylinders  of  the  intestinal  epithelium  viewed  by  their  free  extremity;  d. 
ditto,  as  seen  in  a transverse  section  of  a villosity. 

The  villi  cannot  be  seen  to  full  advantage  except  they  be  erected 
by  an  injection,  in  which  case  those  of  the  upper  part  of  the  small 
intestine  are  found  to  run  into  each  other  very  much  like  the  con- 
volutions of  the  cerebrum,  and  to  press  upon  each  other’s  sides  in 
the  same  way.  Some  of  them,  however,  are  merely  semi-oval 
Vol.  II.— 6 


54 


ORGANS  OF  DIGESTION; 


plates,  the  transverse  diameter  of  which  exceeds  the  length  or  ele- 
vation. At  the  lower  end  of  the  small  intestine  they  become  sim- 
ply conical  projections,  somewhat  curved,  with  the  edges  bent  in 
or  concave,  and  they  retain  this  mechanism  until  they  entirely  dis- 
appear near  the  ileo-colic  valve.  In  the  whole  length  of  intestine 
there  is,  however,  every  variety  of  shape  of  villi,  from  oblong  curved 
and  serpentine  ridges,  to  the  laterally  flattened  cone  standing  on  its 
base ; the  first  condition  changing  gradually  to  the  last  in  the  de- 
scent of  the  bowel.  Conformably  to  this  definition  of  villi,  none 
exist  either  in  the  stomach  or  colon,  for  there  we  have  only  the 
venous  mesh.  The  villi  of  the  jejunum  are  about  the  thirtieth  of 
an  inch  high,  and  those  of  the  ileum  about  one-sixtieth. 

In  the  ileum,  the  superficial  venous  layer  has  great  regularity  and 
the  conical  villi  stand  out  beautifully  from  its  anastomoses,  or  in 
equivalent  language,  from  the  divisions  of  the  follicles.  In  the 
upper  part  of  the  small  intestine  the  follicles  are  in  equal  number 
to  what  they  are  in  the  ileum  ; the  regularity  of  their  arrangements 
being  interrupted  by  the  long  serpentine  and  oval  villi;  but  invaria- 
bly the  same  venous  intertexture  exists  and  forms,  in  both  parts,  the 
chief  bulk  of  the  villi,  by  passing  into  them. 

In  the  stomach  the  follicles  vary  much  in  size,  and  there  is  an 
arrangement  whereby  many  of  the  smaller  ones  are  seen  to  open  into 
the  larger:  on  an  average  about  two  hundred  and  twenty-five  are 
found  upon  every  square  of  one  eighth  of  an  inch,  which  would  give 
of  course  to  an  inch  square  sixty-four  times  that  amount,  or  fourteen 
thousand  four  hundred  follicles.  Conceding  the  wThole  stomach  to 
present  an  area  of  ninety  inches,  which  is  probably  below  the  mark 
when  this  organ  is  moderately  distended,  as  exhibited  in  the  prepa- 
ration upon  which  this  calculation  is  founded,  the  entire  number  of 
follicles  is  one  million  two  hundred  and  ninety-six  thousand. 

The  great  uniformity  of  size  of  these  follicles  in  the  colon,  and 
its  even  surface,  enable  us  to  count  them  with  more  certainty,  and 
they  appear  to  exist  at  the  beginning  of  this  gut  at  the  rate  of  about 
four  hundred  for  every  eighth  of  an  inch  square,  but  in  the  sigmoid 
flexure  at  the  rate  of  about  two  hundred  to  the  same  area  ; they  be- 
come, in  fact,  both  smaller  and  less  numerous  in  descending  towards 
the  anus.  Their  average  may  be  stated,  therefore,  as  three  hundred 
for  every  one-eighth  of  an  inch  square — and  as  nineteen  thousand 
two  hundred  for  every  inch  square.  Admitting  the  entire  area  of 
the  colon  to  be  five  hundred  inches,  and  nineteen  thousand  two 


ANATOMY  OE  THE  MUCOUS  COAT. 


55 


hundred  of  these  follicles,  to  exist  on  every  inch  square,  the  aggre- 
gate number  will  be  nine  millions  six  hundred  and  twenty  thousand. 

In  the  colon  the  resemblance  is  almost  exact  with  what  is  called 
the  perforated  card  or  Bristol  board,  used  by  ladies  for  working  em- 
broidery or  variegated  needle-work. 

Again,  estimating  the  whole  area  of  the  mucous  coat  of  the  small 
intestine  at  fourteen  hundred  and  forty  inches,  and  allowing  for  in- 
terruptions occasioned  by  villi;  about  three  hundred  and  ninety  fol- 
licles exist  upon  every  one-eighth  of  an  inch  square,  or  24,960  upon 
an  inch : say  then,  that  about  twenty-five  thousand  follicles  are  found 
upon  every  square  inch,  and  the  two  numbers  multiplied,  produce 
thirty-six  millions. 

The  entire  number  of  follicles  in  the  whole  alimentary  canal,  is, 
by  the  preceding  estimates,  forty-six  millions  nine  hundred  thousand , 
and  upwards.  I am  very  far  from  pretending  to  have  counted  them 
all,  but  have  made  an  approximation  to  the  actual  number  by  ob- 
serving sections  of  different  portions  of  the  same  subject,  and  verify- 
ing the  observations  upon  other  subjects. 

The  external  surface  of  the  cutis  vera  presents,  as  it  were,  in 
outline,  the  same  follicular  arrangement;  the  venous  reticular  inter- 
texture  appearing  broader,  not  quite  so  perfect,  and  more  shallow, 
and  forming  the  papillae  ; but  as  additional  experiments  are  wanting, 
it  may  be  passed  over  with  this  transient  notice  ; perhaps,  in- 
deed, a more  skilful  hand  in  adopting  the  hint  may  perfect  the 
details.* 

In  the  stomach,  the  largest  of  these  follicles  is  about  one-ninety 
eighth  of  an  inch  in  diameter,  and  the  smallest  about  one-four  hun- 
dred and  ninetieth.  In  the  colon  the  largest  is  about  one-two  hun- 
dred and  forty-fifth  of  an  inch  in  diameter,  and  the  smallest  about 
one-four  hundred  and  ninetieth.  In  the  small  intestines  their  size 
varies  in  about  the  same  ratio  as  in  the  colon,  but  they  are  much 
more  irregular  in  shape,  being  scattered  more  in  groups,  in  conse- 
quence of  the  villi  intervening:  some  of  them  penetrate  obliquely 
towards  the  foundations  of  the  villi ; hence,  when  examined  from  the 
exterior,  their  distribution  is  more  regular,  and  they  are  seen  lodged 
in  the  cellular  coat  of  the  gut. 

I have  endeavoured  to  keep  the  estimate  of  the  number  of  folli- 

* It  is  probably  this  which  constitutes  the  bloody  pimples  (bourgeons 
sanguins)  of  the  skin. 


56 


ORGANS  OF  DIGESTION. 


cles  below  what  other  calculators  would  make  it  upon  an  observa- 
tion of  my  preparations,  and  a fair  measurement  of  the  area  of  the 
alimentary  canal,  lest  the  number  may  seem  excessive  and  incredi- 
ble ; I have,  therefore,  the  most  reasonable  assurance  of  being  within 
bounds  on  that  point.  I may  now  ask  their  use  ; is  it  to  secrete  or 
absorb  ? If  they  are  simply  secernents  of  mucus,  the  number,  one 
would  think,  much  greater  than  so  limited  a secretion  requires — 
moreover,  why  is  it  that  they  become  smaller  and  less  numerous 
towards  the  lower  end  of  the  large  intestine,  where  greater  lubri- 
cation is  required  for  hardened  faeces ; in  addition,  are  not  the  glands 
of  Brunner,  (solitaries,)  and  of  Peyer,  ( agminatce ,)  amply  sufficient 
ro  furnish  the  required  mucus?  Again,  after  most  sedulous  obser- 
vations upon  the  villi  of  all  kinds,  finely  erected  by  my  injections, 
and  placed  under  most  accurate,  simple,  and  compound  micro- 
scopes, I find,  invariably,  a polished  reflecting  surface,  uninterrupted 
by  foramina,  either  at  their  ends  or  sides,  while  many  of  these  fol- 
licles are  found  passing  obliquely  into  their  bases.  An  excellent 
Woollaston’s  doublet,  which  makes  the  villi  of  the  ileum  appear  an 
inch  long,  exhibits  them  with  a polished  translucent  surface,  without 
foramina,  except  where  a villus  from  accident  has  been  broken, 
a contingency  readily  recognised  by  one  in  the  habit  of  viewing 
them.  Finally,  if  the  lacteal  foramina  of  Lieberkuhn  and  others, 
do  really  exist,  why  is  it  that  the  raising  of  the  intestinal  epidermis  by 
inflation,  does  not  exhibit  these  foramina  by  the  air  escaping  through 
them,  but,  on  the  contrary,  admits  of  a dried  preparation  in  that 
state,  the  villi  being  completely  effaced.* 

Taking  into  consideration  these  several  objections  to  the  theory 
of  the  follicles  being  secreting  orifices,  it  appears  to  me  that  a better 
idea  of  their  use  is  called  for,  which  suggestion  is  submitted  to  the 
profession,  with  the  hope  that  a more  capable  person  will  remove 
the  difficulty,  by  additional  confirmation  of  preceding  theories,  or 
by  the  invention  of  a new  one  ; for  my  own  part,  I am  much  inclined 
to  adopt  the  opinion  of  their  absorbing  faculties.  It  is  generally  con- 
ceded that  the  erection  and  prehension  of  the  Fallopian  tube  is  pro- 
duced by  a vascular  turgescence,  in  which  the  veins,  from  their  num- 
ber, must  execute  an  important  part ; in  like  manner,  as  these  intes- 
tinal follicles  are  formed  in  the  midst  of  veins,  their  orifices  only  be- 

* In  these  and  other  microscopical  observations,  I owe  much  to  my  friend, 
Dr.  Paul  Beck  Goddard,  now  Professor  of  Anatomy  in  the  Franklin  Medical 
College  of  Philadelphia. 


ANATOMY  OF  THE  MUCOUS  COAT. 


57 


come  erect  and  patulous  by  the  distention  of  those  veins,  and  can- 
not be  well  seen  by  the  eye  alone,  especially  in  the  small  intestine, 
unless  an  injection  has  succeeded  fully;  but  the  erection  of  these 
veins  during  digestion  puts  the  follicles  in  a similar  condition ; there 
is,  therefore,  some  ground  of  inference,  that  the  act  of  the  Fallopian 
tube  in  conveying  a germ,  and  of  a follicle  in  conveying  into  the 
thickness  of  an  intestine  congenial  matter,  may  be  analogous. 

The  follicles  would  seem  at  least  not  to  be  essential  to  the  secre- 
tion of  mucus,  as  it  is  found  where  the  follicles  do  not  exist;  for  ex- 
ample, in  the  frontal,  maxillary  and  sphenoidal  sinus,  and  also  in 
the  cavity  of  the  tympanum. 

Notwithstanding  the  facility  with  which  we  can  detect  these  folli- 
cles, I have  failed  entirely  under  various  means  of  examination,  in 
finding  any  orifices  to  Peyer’s  glands,  in  the  dried  intestine : they 
appear  to  be  merely  small  lenticular  excavations*  in  its  substance, 
and  wherever  a cluster  of  them  exists,  it  disturbs  the  arrangement 
of  the  villi,  and  gives  to  them  a scattered  unequal  distribution.  1 
would  also  suggest  very  respectfully  to  anatomists  whether  our  know- 
ledge in  regard  to  them  is  sufficiently  exact  to  render  farther  inquiry 
useless?  for  my  own  part  it  appears  that  this  subject  requires  some 
additional  attention.  As  they  are  found  closed  the  probability  is 
that  their  contents  are  discharged  when  required,  by  a regular  dehis- 
cence. 

The  above  view,  relative  to  the  alimentary  mucous  membrane, 
presents  at  least  a degree  of  novelty,  by  determining,  with  some  pre- 
cision, the  whole  number  of  the  Gastro-enteric  Follicles  of  the  human 
body,  or  Follicles  of  Lieberkuhn,  and  how  they  are  in  every  instance 
formed  by  meshes  of  veins;  while  the  arteries  enter  only  inconsidera- 
bly into  the  composition  of  the  same  mucous  membrane,  to  an 
amount  in  some  measure  comparable  to  the  presence  of  the  arteries 
in  other  erectile  tissues,  as  the  corpus  spongiosum  and  cavernosum 
penis.  In  the  latter  it  is  familiar  to  every  practised  anatomist,  that 
the  branches  of  the  arteries  are  but  small,  as  they  terminate  in  the 
cells  of  the  penis,  which  are  to  be  considered  as  only  a modification 
of  the  incipient  stage  of  venous  trunks.  If  the  corpus  spongiosum 
were  in  fact  spread  out  into  a thin  and  single  membrane,  so  as  to  line  a 

* This  observation  has  been  confirmed  in  Germany  by  Boehm,  who  has, 
come  to  the  same  conclusion.  He  says  that  they  contain  a white  milky  and 
rather  thick  fluid,  with  numerous  round  corpuscles  of  various  sizes,  but  mostly 
smaller  than  blood  globules.  Am.  Journ.  Med.  Se.  vol.  xxi.  p.  218. 

6* 


jS 


ORGANS  OF  DIGESTION. 


hollow  viscus,  it  would  present  no  very  undue  representation  of  what 
I have  denominated  the  superficial  venous  layer  of  the  alimentary 
canal ; it  being  also  admitted  that  within  the  circuit  of  every  anas- 
tomosis, a follicle  was  formed. 

Viewed  on  the  preparations  of  the  mucous  membrane  of  the  small 
and  large  intestines  which  I have,  these  follicles  appear  like  puncta 
laohrymalia  disseminated  by  thousands  over  every  inch  square,  and 
existing  so  invariably  upon  every  part,  that,  as  I have  stated,  the 
smallest  calculation  of  their  numbers  puts  them  at  from  forty  to  fifty 
millions. 

It  may  be  stated  incidentally,  that  it  is  the  whole  of  this  vascular  and 
follicular  structure,  endowed  with  vital  actions  the  most  important  to 
life,  and  presenting  in  the  aggregate  an  area  of  about  thirteen  square 
feet,  the  size  of  a small  breakfast  table ; whose  morbid  derangements 
constitute  the  essential  features  of  Asiatic  cholera.*  It  has  been 
shown  in  some  of  my  dissections,  that  this  apparatus  in  the  pro- 
gress of  cholera  is  detached  entirely  from  the  stomach  and  colon,  in 
consequence  of  the  excessive  actions  going  on  in  them.  The  small 
intestines  also,  in  some  of  my  preparations,  exhibit  in  patches  a 
similar  phenomenon ; but  as  the  entire  observation  has  been  pre- 
sented to  me  in  its  true  light  only  since  the  disappearance  of  the 
disease,  I have  had  no  means  of  ascertaining  the  extent  to  which 
they  suffer  in  this  way. 

The  anatomy  of  the  muciparous  system  of  the  alimentary  canal 
unquestionably  requires  a more  exact  attention  than  is  generally 
bestowed  upon  it,  and  especially  so  as  to  distinguish  between 
that  part  which  is  really  glandular,  and  the  foramina  or  follicles  now 
under  consideration.  The  following  extract  will  explain  the  diffi- 
culty which  exists  with  some  in  regard  to  a proper  conception  of  the 
latter. 

“The  mucous  glands,  called  also  follicles  or  cryptse  mucosae,  are 
to  the  membranes  of  that  name  what  the  sebaceous  follicles  are  to 
the  skin ; that  is  to  say,  folds  of  the  mucous  membrane  in  form  of 
a cul-de-sac , whose  orifices  open  upon  that  membrane.  These  folli- 
cles have  not  yet  been  discovered  over  the  whole  surface  of  the  mucous 
membrane;  but  here,  as  with  the  skin,  analogy  leads  us  to  admit 
them.  It  is  not  long  since  they  have  been  discovered  in  the  pitui- 
tary membrane,  where  their  existence  had  been  denied.  Be  this  as 

* For  illustrative  preparations  by  the  author,,  see  Wistar  Museum. 


ANATOMY  OF  THE  MUCOUS  COAT. 


59 


it  may,  we  shall  use  the  same  observation  upon  these  glands  that 
was  made  on  the  sebaceous,  viz.,  the  impossibility  of  making  an 
exact  dissection  of  the  capillary  tissues  does  not  allow  us  to  discover 
all  the  forms  of  animal  matter  ; but  wherever  a particular  humour  is 
found  in  a tissue,  we  are  forced  to  conclude  that  this  latter  is  or- 
ganized in  such  a manner  as  to  be  able  to  produce  it,  and  when  in 
place  of  one  humour  we  meet  with  many,  we  must  acknowledge 
that  the  tissue  is  complex.  Such  is  precisely  the  case  with  the  mu- 
cous membrane  of  the  digestive  canal,  and  especially  of  the  stomach, 
which  could  have  a form  of  animal  matter  calculated  to  furnish  di- 
gestive juices,  although  no  gland  destined  to  that  purpose  is  dis- 
coverable.”* * * § 

In  infancy,  especially,  the  mucous  glands  have  a sensible  thick- 
ness, which  enables  us  to  see  them,  but  the  smallest  of  them  require 
the  aid  of  a microscope,  and  appear  to  have  been  described  by 
Galeati.f  As  the  paper  is  not  to  be  had  in  any  of  the  public  libra- 
ries of  this  city,  I can  only  quote  from  it  on  the  current  authority  of 
anatomical  works.  In  a note  to  the  anatomy  of  the  human  body  by 
Sir  Charles  Bell,  article  Intestine,  it  is  stated  as  follows: — “It  has 
been  supposed  that  the  fluids  excreted  from  the  surface  of  the  intes- 
tines were  furnished  by  very  minute  foramina,  (which  are  visible  by 
particular  preparations,)  in  the  interstices  of  the  villi.  See  the  letter 
of  Malpighi  to  the  Royal  Society  of  London  on  the  pores  of  the  sto- 
mach, and  the  paper  by  M.  Galeati  in  the  Bologna  Transactions,  on 
the  inner  coat,  which  he  calls  the  cribriform  coat.  The  pores,  ac- 
cording to  Galeati,  are  visible  through  the  whole  tract  of  the  canal 
and  particularly  in  the  great  intestines.”  Meckel  designates  these 
as  glandular  bodies  under  the  name  of  glandules  mucosa , crypta  mi- 
nima. Another  order  of  glands  are  those  of  Brunnei’4  They  are 
readily  found  in  the  duodenum  at  all  ages  ; and  particularly  well  in 
infancy,  as  low  down  as  the  ileo-colie  valve.  The  third  order  are 
the  glands  of  Peyer,  discovered  in  1677. § The  celebrated  Ruysch 
appears  also  to  have  understood  the  existence  of  the  follicles  of  the 
stomach,  and  Swammerdam  to  have  had  some  idea  of  those  of  the 

* Broussais’  Physiology.  First  American  edition,  p.  419. 

f Be  cornea  ventriculi  et  intestinorum  tunica.  Comm.  Bonon.,  1745. 

f Glandule  intestini  duodeni  vel  pancreas  seeundarius;  discovered  in  1715. 
See  Mangetus,  Theat.  Anat. 

§ See  also  Mangetus  for  the  description  from  Peyer. 


60 


ORGANS  OF  DIGESTION. 


small  intestines,* * * §  and  he  calls  them  tubuli  glandulosi  intestinorum  in- 
teriors. I may  here  remark,  that  the  figure  of  the  villi  of  the  small 
intestines  given  byHedwig,  in  his  Disquisit.  Ampullarum,  &c.  1797, 
and  which  appears,  from  its  introduction  into  Caldani’s  and  M.  Jul. 
Cloquet’s  Anatomy,  to  have  a classical  value,  is,  judging  from  my 
own  preparations,  too  much  a work  of  the  imagination,  executed 
under  probably  some  fallacious  views  of  the  part  itself:  a cluster  of 
cylindrical  villi,  with  holes  at  the  ends,  would  be  an  anomaly,  for 
those  of  the  upper  part  of  the  intestines  are  either  serpentine  folds,  as 
represented  in  my  preparations,  with  branches  running  into  contigu- 
ous folds ; or  semi-oval  laminae ; while  those  lower  down  are  of  a 
flattened  conical  shape,  somewhat  bent,  but  in  every  instance  they 
are  destitute  of  what  has  been  termed  by  Lieberkuhn  an  ampulla, 
and  to  my  eye  as  stated  have  uniformly  polished  surfaces,  uninter- 
rupted by  foramina. 

Mascagni  has  also  introduced  views  of  a good  kind  in  regard  to 
the  follicular  structure  of  the  stomach  and  colon. f But  it  is  to  Sir 
Everard  Home,  that  we  are  indebted  for  one  of  the  best  papers  on 
the  glandular  structure  of  the  stomach  of  different  anirnals.j; 

As  the  real  muciparous  glands  have  an  orifice  leading  into  each 
by  the  admission  of  anatomists,  the  follicles  described  commonly 
by  them,  are  of  this  description,  and  are  not  comparable  in  number 
to  the  follicles  found  in  the  venous  meshes.  The  highest  estimate 
of  the  number  of  the  former,  as  made  by  M.  Lelut,  fixes  them  at 
about  forty-two  thousand. § In  consulting  many  of  the  distinguished 
modern  authorities  on  this  subject,  there  seems  to  be  scarcely  any 
thing  in  the  anatomy  of  the  intestinal  canal  which  is  presented  in 
a more  indefinite  way;  especially  in  regard  to  the  small  intestines, 
than  the  difference  between  the  follicles,  properly  speaking,  and  the 
glands;  and  none  of  them,  so  far  as  I know,  have  previously  to 
myself  undertaken  to  approximate  the  entire  number  of  the  follicles 
and  to  point  out  how  each  one  is  the  centre  of  a venous  anasto- 
mosis, is  formed  by  it,  and  always  exhibits  itself  in  a collapsed  state 
when  the  vein  is  not  turgid.  || 

* Mangetus  Theat.  Anat.  Vol.  I.  p.  310. 

f Prodromo  della  grande  anatomia.  Tab.  xiii. 

X Phil.  Trans.  1807  and  1817;  and  also  his  Comparative  Anatomy. 

§ Bouillaud,  Traite  du  Cholera,  p.  256. 

II  The  anatomy  of  the  Gastro-intestinal  mucous  membrane  has  elicited 


HISTOLOGY  OF  MUCOUS  MEMBRANES. 


61 


SECT.  IV. — HISTOLOGY  OF  MUCOUS  MEMBRANES. 

The  extent  of  the  mucous  coat  of  the  alimentary  canal,  and  the 
important  and  varied  sympathies  which  it  has  with  most  other  parts 
of  the  body,  render  proper  some  remarks  on  membranes  of  this  kind, 
generally.  Mucous  Membranes  are  so  called  from  the  nature  of  the 
secretion  which  they  furnish:  and  the  term  having  been  first  applied 
to  the  lining  coat  of  the  nose,  a similitude  of  character  has  caused 
its  extension  to  that  of  other  organs.  The  celebrated  Bichat,  the 
founder  of  the  science  of  general  anatomy,  was  the  first  to  adopt 
fully,  and  to  perceive  the  value  of  this  classification ; since  which 
it  has  been  almost  universally  received  by  anatomists. 

As  the  skin  forms  an  external  covering  to  the  body,  so  mucous 
membrane  lines  the  internal  surface  of  the  hollow  viscera.  When 
it  is  recollected  that  this  membrane  forms  an  internal  tegument  to 
the  whole  alimentary  canal,  from  the  mouth  to  the  anus;  to  all  the 
urinary  and  genital  apparatus;  to  the  whole  respiratory  system,  from 
the  nose  down  the  trachea  and  throughout  the  lungs;  it  will  be 
admitted  that  its  extension  exceeds  much  that  of  the  skin. 

A mucous  membrane  presents  two  surfaces,  one  of  which  adheres 
to  the  contiguous  parts,  and  the  other  is  free  by  being  internal.  The 
adherent  surface  is  attached  by  a cellular  structure  somewhat  con- 
densed. This  cellular  structure  is  principally  remarkable  for  its 
want  of  disposition  to  secrete  fat  into  its  interstices;  a property  of 
immense  importance,  as  without  it,  obstructions  would  be  con- 
tinually occurring  to  the  destruction  of  life:  it  is  pervaded  by  a 
multitude  of  fine  vessels  and  nerves,  running  forward  to  be  spent 
upon  the  mucous  membrane  ; and  has  been  unfortunately  named 
nervous  coat , by  anatomists  of  high  authority.  The  strength  of  at- 

several  good  papers  in  Europe  since  1835,  inclusive,  the  period  of  my  own 
publication,  which  was  in  anticipation  of  the  others.  In  point  of  date  they 
are  rather  confirmatory  of  preceding  observations  than  distinguished  by  novel- 
ties, and  the  venous  anastomosis  does  not  seem  to  be  understood  or  appreciated, 
except  by  Dr.  Gaddi,  of  Modena,  alluded  to  in  a preceding  note.  In  addition 
to  the  authorities  already  quoted,  the  reader  may  advantageously  consult  Boehm 
de  Gland,  Intest.  Struct.  Penit.  Berol,  1835.  Boyd  on  the  Structure  of  the 
Mucous  Membrane  of  the  Stomach,  Edinburgh,  Med.  and  Surg.  Journal,  1836. 
Likewise  Recherches  Anatorniques  sur  la  Membrane  Muqueuse,  &c.,  par  M. 
Natalis  Guillot  in  L’Experience,  p.  161.  Paris,  1837-8,  and  Muller’s,  Archives, 
1838  and  1839. 


6-2 


HISTOLOGY  OF  MUCOUS  MEMBRANE. 


tachment  which  it  furnishes  is  somewhat  varied ; for  example,  in  the 
small  intestinal  canal  I have  often  seen  the  mucous  membrane  caught 
at  one  end  and  entirely  withdrawn  from  the  muscular  coat,  an  ex- 
periment which  alone  can  give  rigid  ideas  of  its  greater  length,  as 
by  it  all  the  duplicatures  or  valvule  conniventes  are  stretched  out. 
The  experiment  succeeds  much  more  certainly  by  the  regular  pres- 
sure of  a column  of  water  between  the  tunics  of  the  intestine.  The 
mucous  membrane  of  most  organs  is  arranged  into  wrinkles  and 
duplicatures,  for  the  purpose  of  augmenting  its  extent.  This  ar- 
rangement prevails  in  the  nose,  and,  as  mentioned,  in  the  oesopha- 
gus, in  the  stomach  and  intestines;  to  say  nothing  of  many  other 
instances  which  are  noticed  in  the  description  of  each  organ.  In 
some  examples,  they  are  permanent,  and,  in  others,  depend  on  the 
state  of  contraction  of  an  exterior  muscular  coat.  The  interior  face 
of  the  mucous  membranes,  allowance  being  made  for  the  inequali- 
ties just  stated,  moreover,  presents,  when  closely  viewed,  an  abun- 
dance of  more  minute  depressions  and  of  elevations,  causing  it  to 
resemble  velvet.  Some  of  these  depressions  are  so  large  as  to  give  it 
a cellular  appearance,*  as  in  many  parts  of  the  intestinal  canal,  and 
in  the  gall-bladder,  and  have  been  particularly  described  by  Sir 
Everard  Home. 

In  regard  to  organization,  the  mucous  membranes  are  of  a soft, 
spongy  consistence  ; easily  yield  to  mechanical  violence  ; and  de- 
pend for  their  strength  upon  the  .surrounding  cellular  coat.  They 
are  not  of  a uniform  thickness ; for  example,  they  are  much  thinner 
in  the  urinary  and  genital  apparatus,  than  in  the  alimentary  canal ; 
they  also  present  some  varieties  of  consistence.  They  yield  very 
readily  to  putrefaction,  and  are  quickly  reduced  to  a pulpy  state 
by  the  action  of  the  mineral  acids.  Caustics  of  all  kinds  act  more 
promptly  on  them  than  on  the  skin,  owing  to  the  protection  of  the 
latter  by  a dry  epidermis ; Bichat  states,  that  in  the  practice  of  the 
Hotel  Dieu,  this  effect  is  frequently  exemplified,  by  the  administra- 
tion of  lunar  caustic  among  the  common  people  for  the  purpose  of 
poisoning.  The  nitric  acid  leaving  the  silver,  quickly  applies  itself 
to  the  mucous  membrane  of  the  stomach,  and  disorganizing  it, 
forms  a whitish  eschar,  which,  if  life  be  preserved  long  enough,  is 
finally  detached  in  a membranous  form. 

* They  are  not  to  be  confounded  with  the  follicles,  but  are  a miniature  re- 
presentation of  what  is  called  tripe,  in  culinary,  language. 


HISTOLOGY  OF  MUCOUS  MEMBRANES. 


63 


One  of  the  remarkable  properties  of  the  mucous  surfaces  of  the 
stomach  and  intestines  is,  that  of  coagulating  milk.  According  to 
the  experiments  of  Spallanzani,  the  gastric  juice,  in  the  living  state, 
assists  in  this  change ; but  it  is  perfectly  well  known  in  domestic 
affairs,  that  the  dried  stomach  of  a calf,  where  the  juices  have  been 
completely  evaporated,  is  also  productive  of  it.  The  observations 
of  the  same  author  led  him  to  conclude,  that  the  peritoneal  and 
the  muscular  tunics  of  the  stomach  are  insufficient  to  produce  this 
effect. 

The  internal  surface  of  the  mucous  membranes  is  furnished  with 
small  projecting  points  or  spiculse,  called  papillae  or  villi.  They 
are  particularly  conspicuous  and  numerous,  as  mentioned,  on  the 
upper  surface  of  the  tongue  and  in  the  small  intestine,  and  bear  an 
analogy  of  function  and  organization  with  the  very  fine  papillae 
which  are  seen  invariably  on  the  surface  of  the  cutis  vera.  These 
papillae  are  constantly  furnished  with  nervous  filaments,  giving 
them  a high  degree  of  sensibility ; and  with  an  abundance  of  blood 
vessels.  The  term  papillae  has  been  more  exclusively  applied  to 
the  projections  on  the  surface  of  the  tongue,  from  their  greater 
size ; they  are  there  also  more  distinctly  covered  with  an  epidermis, 
frequently  called  epithelium,  or  periglottis.  The  villi,  from  their 
connexion  with  the  process  of  digestion,  have  been  emphatically 
denominated  the  roots  of  animals.  According  to  M.  Beclard,* 
who  has  examined  them  upon  a plan  of  his  own  contrivance  well 
suited  to  accurate  microscopic  observations,  they  are  presented 
under  a diversity  of  shapes.  Those  of  the  pyloric  half  of  the  sto- 
mach, and  of  the  duodenum  being  broader  than  they  are  long,  are 
composed  of  very  small  thin  laminae,  having  a tufted  arrangement. 
Those  of  the  jejunum  are  long  and  narrow,  having  more  the  form 
commonly  assigned  to  them,  while  in  the  lower  part  of  the  ileum 
and  in  the  colon  they  again  become  laminated. 

It  should  be  observed,  that,  notwithstanding  the  assertion  of 
Leeuwenhoek,  Hewson,  Hunter,  and  others,  tire  fact  is  still  called  in 
question,  by  many  of  the  most  distinguished  anatomists  of  the 
present  time,  MM.  Beclard,  J.  F.  Meckel,  Rudolphi,  Muller,  &c., 
whether  the  orifices  of  the  lacteals  are,  under  any  circumstances, 
visible  on  the  surface  of  the  villi.  Admitting  that  they  do  not  open 


* Anat.  Gen.  p.  253.  These  notions  are  not,  however,  in  unison  with  my 
own,  as  just  stated.  Sect.  III. 


64 


HISTOLOGY  OF  MUCOUS  MEMBRANE. 


as  stated,  the  power  of  interstitial  absorption  in  the  mucous  mem- 
brane will  still  account  for  the  chyle  finally  getting  in  the  lacteals,  as 
well  as  for  fluids  passing  into  the  circulation  from  the  stomach,  when 
its  continuity  with  the  intestinal  canal  has  been  interrupted.* 

The  Epidermis  or  Epithelium  of  mucous  membranes  is  very  dis- 
tinct at  their  external  orifices,  but  becomes  less  and  less  apparent 
towards  the  interior  of  tire  body,  until  it  finally  cannot  be  distin- 
guished by  the  eye  alone ; and  anatomists  of  a former  period  generally 
considered  that  it  is  entirely  deficient,  notwithstanding  the  assertion 
of  Haller  to  the  contrary.  It  is  a matter  of  common  observation, 
that  when  the  interior  of  mucous  membranes  is  exposed  by  an  ever- 
sion for  a long  time,  to  the  action  of  the  atmosphere ; they  take  on 
more  of  the  structure  of  skin,  and  become  evidently  covered  with  a 
cuticle  which  protects  them  and  diminishes  their  secretion.  This  is 
exemplified  in  eversion  of  the  vagina  from  prolapsed  uterus,  in  elon- 
gated and  tumid  labia  interna,  and  in  other  ways : restore  the  parts 
to  their  natural  situation,  and  they  are  brought  back  to  their  original 
structure.  In  the  partial  prolapse  of  the  mucous  membrane  of  the 
rectum,  from  piles,  corresponding  circumstances  occur.  From  this 
we  infer,  that  the  full  development  of  cuticle  depends  very  much 
upon  the  degree  of  exposure  which  any  surface  of  the  body  has  to 
undergo.  The  reverse  also  takes  place : shut  up  or  close  any  sur- 
face of  the  skin  so  that  it  is  put  in  the  condition  of  an  interior  cavity, 
and  it  immediately  begins  to  assimilate  itself  to  a mucous  membrane. 
This  is  proved  by  the  tendency  in  young  children  to  a detachment 
of  the  cuticle,  or  excoriation  of  the  opposed  surfaces  of  the  deep 
wrinkles  about  their  thighs  and  in  their  perineum  ; a tendency  obvia- 
ted by  the  nursery  practice  of  covering  these  surfaces  with  powdered 
starch.  It  is  also  manifested  frequently  in  the  dressing  of  wounds 
with  sticking  plaster,  where  an  incautious  approximation  of  the  con- 
tiguous surfaces  of  the  skin,  not  only  is  followed  by  excoriation,  but 
even  by  ulceration.  The  existence  of  an  epithelium  every  where  on 
mucous  membranes,  now,  is  definitely  settled  by  microscopical  ob- 
servers, and  has  become  one  of  the  most  established  points  of 
anatomy.  This  epithelium  is  formed  by  a continuous  layer  of  cells 
not  only  in  the  gastro-intestinal  mucous  membrane,  but  in  the  va- 
rious prolongations  of  the  latter  into  the  ducts  of  the  proximate  glands 

* Should  the  suggestion  of  the  absorbing  powers  of  the  gastro-enteric  fol- 
licles which  I have  proposed  in  Section  third,  be  correct,  it  will  dispose  of  the 
difficulties  and  opposing  opinions  alluded  to  in  this  paragraph. 


HISTOLOGY  OF  MUCOUS  MEMBRANES. 


65 


and  in  fact  a similar  arrangement  exists  wherever  a mucous  mem- 
brane is  found.  These  cells  are  according  to  some  the  emanation 
of  an  amorphous  basement  membrane,  they  execute  the  specific 
secretion  of  the  part  which  they  cover,  and  thus  whatever  may  be 
the  similitude  of  their  structure,  perform  very  varied  offices. 

Varieties  of  Cells  or  Corpuscles  forming  the  epithelium  of  Mucous 
Surfaces.  From  Henle. 

Fig.  24.  Fig.  25. 


Fig.  24 — a,  5,  e,  d,  e,  f.  Nucleated  ciliary  cells;  their  free  end  straight 
and  furnished  with  filaments,  called  Cilia,  of  different  shapes,  a,  Nucleus. 

a , Cilia. 

Fig.  25. — A row  of  ciliated  cells,  rounded  at  end.  a,  In  a line  with  nuclei. 

b.  Cilia. 

Fig.  26. — Cylindrical  cells  apart  with  their  nuclei. 

Fig.  27. — Cylindrical  cells  grouped  compactly,  a,  Bodies.  6,  Free  extre- 
mities. 

The  mucous  membranes  vary  in  colour  from  a very  light  pink  to 
a deep  red,  which  is  owing  to  the  blood  that  circulates  in  them.  In 
cases  of  suffocation,  they  become  almost  brown  from  the  congestion  of 
blood  in  them,  while  in  fainting  they  turn  white  from  the  desertion 
of  the  latter.  The  vessels  after  having  penetrated  the  thickness  of 
the  membrane,  ramify  with  extreme  minuteness  on  its  surface.  The 
veins  in  an  injection  invariably  predominate  over  the  arteries  by  their 
greater  size  and  distensibility.  In  consequence  of  their  superficial 
situation,  the  vessels  being  unsupported  on  one  side,  are  exposed  to 
rupture  from  slight  concussions  ; in  this  way  hemorrhage  is  produced 
in  the  lungs  from  coughing ; and  bleeding  at  the  nose  from  blows 
upon  the  head. 

Exhalant  orifices  exist  in  great  numbers  in  the  mucous  membranes : 
this  is  especially  the  case  in  the  lungs,  where  the  pulmonary  perspi- 
ration, as  it  is  called,  is  very  obvious  to  common  observation.  Else- 
Vol.  II.— 7 


ORGANS  OF  DIGESTION. 


(>() 

where,  this  discharge  is  so  much  blended  with  the  mucus  of  the  part, 
that  it  is  difficult  to  appreciate  its  quantity.  From  the  superficial 
situation  of  the  blood  vessels,  it  is  clear  that  the  exhalant  orifices  or 
pores,  have  but  a short  course  to  run.  This  is  considered  by  Bichat 
as  a satisfactory  reason  for  the  tendency  of  the  blood  to  escape  through 
them,  or  to  ooze  out  where  there  is  no  rupture. 

Absorbents  exist  also  in  great  numbers,  as  proved  by  the  absorp- 
tion of  chyle,  of  watery  drinks  from  the  intestinal  canal,  and  by  the 
inhalation  of  the  vapour  of  spirits  of  turpentine  into  the  lungs,  rapidly 
communicating  the  particular  smell  of  this  article  to  the  urine.  There 
are,  moreover,  cases  recorded  of  obstructed  urethra,  where  the  urine 
has  been  almost  entirely  absorbed  by  the  mucous  coat  of  the  bladder. 

In  regard  to  nerves,  the  mucous  membranes  are  well  furnished 
with  them.  Bichat  has  remarked  that  wherever  these  membranes 
are  situated  near  the  surface  of  the  body  and  enjoy  common  sen- 
sibility, they  are  almost  wholly  furnished  from  the  central  portions 
of  the  nervous  system,  as  the  brain  and  spinal  marrow : this  is  ex- 
emplified in  the  conjunctiva,  the  pituitary  membrane,  the  palate, 
the  glans  penis,  &c.  On  the  contrary,  the  sympathetic  nerve  fur- 
nishes the  intestines,  the  bladder,  and  the  excretory  tubes  gene- 
rally. 

Mucous  Glands,  as  they  are  called,  exist  throughout  the  system 
of  mucous  membranes,  being  situated  either  under  them  or  in  their 
thickness.  From  them  is  derived  the  mucilaginous  fluid  which 
lubricates  so  abundantly  their  interior  surfaces,  as  to  facilitate 
the  passage  of  extraneous  bodies,  and,  at  the  same  time,  to  protect 
the  membrane  from  mechanical  violence.  These  glands  are  of 
various  sizes,  from  that  of  the  tonsils  and  the  muciparous  glands 
on  the  lips,  cheeks,  and  root  of  the  tongue,  to  the  almost  impercep- 
tible cryptse  of  the  bladder  and  urethra.  Their  shape  is  either 
lenticular,  rounded,  or  that  of  a pouch.  The  former  two  have 
l heir  parietes  of  a sensible  thickness,  but  the  last  are  too  thin  to  be 
distinguished  from  the  mucous  membrane  itself.  For  the  most  part, 
the  excretory  duct  of  these  glands  is  short  and  patulous,  so  as  to 
lead  directly  into  the  substance  of  the  gland.  This  is  remarkably 
the  case  with  the  tonsils,  which  consist  in  a congeries  of  these  fol- 
licles; and  with  the  glands  on  the  root  of  the  tongue.  In  some 
animals  they  are  so  numerous  as  to  form  almost  a distinct  lamina  to 
the  intestines ; after  the  manner  of  the  human  subject,  on  the  palate 
and  parietes  of  the  mouth. 


THE  LIVER. 


67 


The  Mucosity  discharged  from  these  glands  is  one  of  the  prin- 
ciples of  animals,  and,  as  is  well  known,  exists  also  to  a great 
extent  in  some  vegetables.  When  perfectly  pure  and  fluid,  it  is 
white,  transparent,  inodorous,  and  insipid.  It  is  insoluble  in  alco- 
hol, but  soluble  in  acids.  Water  forms  more  than  nine-tenths  of 
it,  the  remainder  is  mucus,  properly  speaking,  blended  with  some 
neutral  salts  of  soda  and  potash. 

The  mucus  which  covers  the  surface  of  the  mucous  membranes 
consists  chiefly  of  separated  particles  of  epithelium  mixed  with  a 
fluid  exudation,  while  the  mucous  follicles  are  said  to  pour  out  a 
fluid  holding  mucous  globules  suspended. 

The  mucous  membranes  are  exposed  to  a multitude  of  morbid 
alterations,  such  as  polypus,  scirrhus,  cancer,  phlegmorrhagia?  or 
serous  fluxes,  blennorrhagise  or  mucous  fluxes,  inflammation  in  all 
its  forms,  gangrene,  ulcerations,  and  congestions. 


CHAPTER  V. 

Of  the  Assistant  Chylopoietic  Viscera. 

SECT.  I. — OF  THE  LIVER.* 

The  Liver  ( Hepnr , Jecur)  secretes  the  Bile,  and  is  the  largest 
glandular  body  in  the  human  frame.  It,  as  mentioned,  occupies 
the  whole  of  the  right  hypochondriac  region,  the  upper  half  of  the 
epigastric,  and,  as  it  becomes  thinner  in  going  towards  the  left  side, 
it  occupies  a small  space  in  the  right  superior  part  of  the  left  hypo- 
chondriac region.  Its  whole  superior  face  is  in  contact  with  the 
diaphragm;  on  the  left  it  is  bounded  by  the  spleen,  and  below  by 
the  stomach,  and  the  transverse  colon ; behind  it,  are  the  vertebral 
column  and  the  ascending  cava. 

The  shape  of  the  liver  is  like  one  half  of  an  ovoidal  body  cut 
into  two  in  the  direction  of  its  long  diameter,  and  having  the  thick- 
end  turned  to  the  right  side.  It  is  about  ten  inches  in  length  bv 
six  or  seven  wide,  and  w’eighs  from  four  to  five  pounds  in  the 

* Anat.  Atlas,  Figs.  339  to  347,  inclusive. 


68 


ORGANS  OF  DIGESTION. 


adult.  Its  colour  is  a reddish  brown,  generally;  though,  on  its 
under  surface  and  about  its  edges,  broad  blue  or  black  patches  are 
constantly  met  with,  which  do  not  indicate  any  morbid  derange- 
ment. 

Its  upper  surface  is  of  an  uniform  convexity,  rather  more  promi- 
nent at  the  right  posterior  part  than  elsewhere  ; adjusts  itself  accu- 
rately into  the  concavity  made  by  the  under  surface  of  the  dia- 
phragm; and  is  unequally  divided  from  before  backwards  by  the 
suspensory  ligament.  The  anterior  margin  is  thin,  and  is  notched 
where  the  suspensory  ligament  begins  ; the  posterior  margin  is  much 
thicker,  and  has  near  its  middle  a broad  depression,  to  fit  it  to  the 
projection  of  the  vertebral  column.  The  ascending  vena  cava 
forms  a superficial  sulcus  upon  this  margin,  and  frequently  there  is  a 
complete  canal  through  the  substance  of  the  liver  for  transmitting 
it.  The  right  extremity  is  very  thick,  and  almost  fills  the  hypochon- 
driac region  of  that  side,  while  the  left  extremity  is  reduced  to  a 
thin,  tapering,  and  flexible  edge. 

The  under  surface  of  the  liver  is  much  more  irregular  than  the 
upper;  it  is  traversed  in  an  antero-posterior  direction,  in  a line  cor- 
responding with  the  attachment  above  of  the  suspensory  ligament, 
by  the  umbilical  fissure,  ( Sulcus  Umbilicalis ) which  extends  from 
the  notch  in  the  front  edge  to  the  depression  behind,  and  obtains  its 
name  from  having  accommodated  in  the  foetal  state,  the  umbilical 
vein,  now  converted  into  a round  ligamentous  cord.  In  the  poste- 
rior part  of  this  fissure  is  likewise  to  be  seen,  in  the  same  condition, 
what  remains  of  the  ductus  venosus.  The  anterior  portion  of  the 
umbilical  fissure  is  notunfrequently  converted  into  a complete  canal, 
by  a portion  of  hepatic  substance  crossing  it  like  a small  bridge. 
The  transverse  fissure  ( Sulcus  Transversus , Intermedins)  is  situated 
in  the  middle  of  the  under  surface  of  the  liver,  and  extends  along  a 
third  or  fourth  of  the  long  diameter  of  the  latter.  It  begins  some- 
what to  the  left  of  the  umbilical  fissure,  and  crossing  it  at  right  angles, 
proceeds  towards  the  right  extremity.  It  contains  the  vena  portarum, 
the  hepatic  artery,  and  the  hepatic  duct,  lymphatics  and  nerves ; all 
of  which  are  bound  to  each  other  by  a close  cellular  substance. 

The  suspensory  ligament  above,  and  the  umbilical  fissure  below, 
give  occasion  to  divide  the  liver  into  Lobes,  Right  and  Left ; of 
which  the  right  is  by  much  the  largest,  and  accommodates  almost 
entirely  the  transverse  fissure,  having  also  on  its  under  surface  some 


THE  LIVER. 


69 


subordinate  elevations,  to  wit,  the  Lobulus  Spigelii  and  the  Lobulus 
Quartus,  together  with  the  Gall-Bladder. 

The  Lobulus  Spigelii  is  placed  between  the  transverse  fissure  and 
the  posterior  margin  of  the  liver,  to  the  right  of  the  posterior  end  of 
the  umbilical  fissure.  Its  shape  is  somewhat  prismatic,  bifurcating 
in  front ; one  of  the  elongations  or  prongs  is  a papilla  overhanging 
the  transverse  fissure,  and  is,  therefore,  considered  as  one  side  of  the 
gate-way  {porta)  opened  for  the  vena  portarum  ; the  other  elongation 
is  a small  ridge,  sometimes  called  Lobulus  Caudatus,  and  is  lost 
gradually  on  the  under  surface  of  the  great  lobe,  by  inclining  to  the 
right. 

The  Lobulus  Quartus,  or  Anonymus,  is  not  by  any  means  so 
elevated  as  the  last,  but  having  a flattened  surface,  is  placed  in  front 
of  the  transverse  fissure,  between  the  fore  end  of  the  umbilical  fis- 
sure and  the  gall-bladder ; its  posterior  extremity  is  the  other  side 
of  the  gate-way  {porta)  of  the  Liver,  and  is  just  opposite  to  that  fur- 
nished by  the  Lobulus  Spigelii. 

The  liver,  from  being  completely  enveloped  in  peritoneum,  has 
a smooth  glossy  appearance.  The  reflections  of  this  membrane, 
from  it  to  die  parietes  of  the  abdomen,  form  the  ligaments,  as  they 
are  called,  which  consist  each  of  two  laminae..  The  Falciform  Liga- 
ment, or  Suspensory,  containing  in  its  anterior  margin  the  remains 
of  the  umbilical  vein,  now  called  Ligamentum  Teres,  begins  at  the 
umbilicus,  extends  from  it  along  the  linca  alba  and  the  middle  line 
of  the  diaphragm,  and,  as  mentioned,  is  reflected  to  the  upper  sur- 
face of  the  liver,  from  the  anterior  to  the  posterior  margin.  The 
Right  Lateral  Ligament  is  situated  behind,  and  departs  from  the  back 
part  of  the  diaphragm  to  the  posterior  margin  of  the  right  lobe.  The 
Left  Lateral  Ligament  also  goes  from  the  back  part  of  the  diaphragm, 
and  is  attached  along  the  posterior  margin  of  the  left  lobe.  Where 
the  suspensory  ligament  inclines  on  each  side  into  the  lateral,  it 
passes  with  so  much  obliquity  as  to  leave  some  portion  of  the  poste- 
rior margin  of  the  liver  uncovered  by  peritoneum  ; the  latter,  where 
it  describes  the  periphery  of  this  space,  has  been  rather  unnecessarily 
designated  as  the-  Coronary  Ligament. 

In  addition  to  the  peritoneal  coat,  the  liver  has.  another,  connect- 
ing it  with  the  peritoneum,  and  seeming  to  be  only  condensed  cellular 
substance,  which  also  penetrates  into  the  substance  of  the  gland,  and 
holds  its  constituent  parts  together.  It  is  particularly  well  seen 
within  the  circle- of  the  coronary  ligament. 


70 


ORGANS  OF  DIGESTION. 


Of  the  Organization  of  the  Liver. 

The  glandular  substance  of  the  Liver  is  fragile  and  easily  lace- 
rated ; and  consists  of  a congeries  of  spheroidal  or  polyhedrical 
grains,  called  by  Malpighi  acini  from  their  resemblance  to  small 
berries ; they  are  best  seen  on  tearing  the  organ,  are  united  in  mass 
by  the  elongations  of  the  cellular  coat,  and  traversed  by  the  trunks 
of  the  blood  vessels.  Each  of  these  granulations  is  about  the  size 
of  a millet  seed,  and  is  a representative  of  the  entire  gland,  as  its 
structure  is  complete  in  itself ; being  formed  by  the  capillary  termi- 
nations of  the  blood  vessels,  and  by  the  origins  of  a branch  of  the 
hepatic  duet,  called  the  porus  biliarus. 

The  liver  is  made  extremely  vascular  by  the  ramifications  of  three 
kinds  of  blood  vessels,  the  Vena  Portarum,  the  Hepatic  Artery,  and 
the  Hepatic  Veins.  The  first  two  convey  the  blood  to  it,  and  the 
third  removes  it  again,  into  the  general  circulation,  by  emptying  into 
the  ascending  vena  cava.  There  are  also  the  commencing  radicles 
of  the  Hepatic  duct;  the  Lymphatic  vessels;  and  the  Nerves. 

When  examined  with  a microscope,  the  acini  are  seen  to  be  made 
of  smaller  graniform  bodies,  and  also  present  under  particular  cir- 
cumstances two  colours,  a brown  and  a yellow.  This  difference  of 
colours,  observed  originally  by  Ferrein,*  gave  occasion  to  the  division 
of  the  substance  of  each  acinus  into  Cortical  (Substantia  corticalis, 
brunnea,)  and  into  Medullary,  (Substantia  medullaris,  flava)  the  pro- 
priety of  which  is,  however,  not  fully  sanctioned  even  at  the  present 
day.  The  Cortical  or  brown  matter  is  the  investment  of  the  other, 
and  depends  for  its  colour,  principally  upon  the  great  proportion  of 
capillary  vessels,  derived  from  the  three  orders,  the  vena  port®, 
arteria  hepatica,  and  vense  hepaticm.  The  Medullary  or  yellow 
matter,  is  the  place  of  origin  of  the  biliary  ducts,  and  is  supposed  to 
derive  its  colour  from  the  presence  of  bile  in  their  radicles. f The 
ground  of  this  distinction  is  so  unsatisfactory  and  it  seems  to  depend 
so  much  upon  some  contingent  condition  of  the  circulation  of  the 
blood,  that  while  it  is  admitted  by  very  eminent  authority,  as  Bichat 
and  J.  F.  Meckel,  it  is  as  earnestly  rejected  by  equally  high,  as 

* Mem.  de  Paris  1735,  Hist.  51. 

f The  application  of  those  terms  has  been  changed,  as  Ferrein  called  the 
brown  matter  the  Medullary,  and  the  yellow,  the  Cortical. 


THE  LIVER. 


71 


Portal  and  E.  H.  Weber.  My  own  observations  have  been  such  as 
to  incline  me  to  the  authority  of  the  two  latter. 

Some  new  microscopic  details  have  been  attached  to  the  account 
of  the  Liver  within  a few  years,  by  Purkinje  and  Henle,  and  are 
fully  confirmed  by  Wagner  and  others. 

The  proper  hepatic  structure,  the  parenchyma  of  the  liver,  it 
would  thus  seem  is  composed  in  the  case  of  each  acinus,  of  a collec- 
tion of  epithelial  cells,  so  near  together  as  to  have  their  shape 
moulded  by  mutual  contact,  and  to  become  polyhedrical.  They 
are  about  the  1-7000  of  a line  in  diameter,  and  have  a nucleus  of 
about  the  fourth  or  fifth  of  that  size.  Hallman  has  placed  these 
structures  at  a much  smaller  size,  about  one-tenth  of  the  diameters 
stated  : and  Wagner  makes  them  much  larger,  amounting  in  fact  to 
1-100  of  a line.  There  are  other  measurements  of  an  intermediate 
kind,  showing  all  together  that  there  are  great  diversities  in  their 
real  magnitude.*  These  cells  have  their  shape  varied  from  a 
flattened  spheroidal  to  a quadrangular  or  pentangular  one,  and  con- 
tain within  them  a yellow  bilious  looking  material,  having  intermixed 
with  it  several  globules  of  fat  large  and  small.  The  biliary  matter 
contained  in  them  is  concluded  to  be  proof  sufficient  of  these  cells 
being  the  real  agents  of  the  secretion  of  bile.  The  essential  features 
of  this  process  then  consists  in  the  successive  evolution  of  these  cells, 
of  their  active  elaboration  of  the  bile — of  their  rupture  or  dehiscence 
and  of  the  further  conveyence  of  the  bile  into  the  pori  biliarii,  by  a 
process  as  yet  not  fully  understood.  The  existence  of  these  hepatic 
cells  is  easily  ascertained:  by  tearing  a liver  especially  a young  one, 
and  then  scraping  it,  they  turn  out  so  abundantly  that  allowance 
made  for  the  blood  vessels,  and  cellular  or  areolar  tissue,  they  seem 
to  compose  it  almost  wholly. 

The  idea  of  Huschke  in  regard  to  their  connexion  with  the  pori 
biliarii  is,  that  the  bile  is  elaborated  in  their  central  nucleus,  as 
proved  by  nitric  acid,  and  that  an  extremely  attenuated  branch  of  a 
bile  duct  1-684  of  a line  in  diameter,  reaches  each  cell,  being  attached 
to  it  like  a pedicle,  and  in  that  way  receives  the  discharge  of  bile.  He 
believes  that  the  fat  of  the  hepatic  cell  or  vesicle,  seen  also  upon  its 
surface,  is  converted  into  bile.  This  view  of  the  terminal  points  of  the 
biliary  ducts  is  very  much  a repetition  of  the  penicillous  structure  of 
former  anatomists,  its  arrangement  being  perhaps  more  attenuated 
than  any  they  had  an  idea  of.  He  says  that  to  the  present  moment 


* Huschke  Traite  de  Splanchnologie,  p.  123. 


72 


ORGANS  OF  DIGESTION. 


lie  has  never  witnessed  the  reticulated  connexion  of  the  fine  extremi- 
ties of  the  bile  ducts  in  their  origin  from  the  acini,  which  are  repre- 
sented in  the  ideal  figure  of  Mr.  Kiernan.  Also  that  he  has  not 
found  the  anastomoses  of  the  larger  bile  ducts,  said  to  have  been 
discovered  by  the  latter,  in  the  left  hepatic  ligament;  and  he  has  been 
equally  unsuccessful  in  detecting  the  communications  said  by  Berres 
to  be,  between  the  blood-vessels  and  the  biliary  ducts. 

My  own  injections  of  the  liver,  considered  by  good  judges  as 
very  successful  and  not  inferior  in  that  respect  to  some  upon  which 
a new  anatomy  of  the  liver  has  been  founded,  exhibit  a very  high 
vascularity  upon  the  periphery  and  in  the  intervals  of  the  acini;  this 
vascularity  falls  off’  much  in  the  substance  itself  of  the  acinus;  and  is 
then  repeated  in  the  centre  of  the  acinus  in  originating  the  corres- 
ponding branch  of  the  hepatic  vein.  These  preparations  are  now 
of  many  years  standing.  A similar  exposition  has  been  made  by  Du- 
jardin  and  Verger,*  who  assert  that  the  parenchyma  of  the  lobules, 
(acini)  is  absolutely  without  vessels  and  interior  plexus,  being- 
made  of  oval  gelatinous  corpuscles,  in  the  intervals  of  which  the 
blood  corpuscles  move. 

The  commencing  radicles  or  ramifications  of  the  Hepatic  Duct , 
take  their  origin  in  the  acini.  The  larger  branches  converge  into 
their  respective  trunks  successively  or  in  pairs  ; while  the  primordial, 
or  most  minute  ones,  converge  several  of  them  to  the  same  point, 
giving  a penicillous  appearance.  These  several  tubes  constitute  the 
Biliary  Pores  (Pori  Biliari)  and  are  always  in  the  same  group  with 
the  branches  of  the  Vena  Portarum  and  Hepatic  Artery.  It  is  un- 
settled whether  these  brush-like  or  penicillous  ends  of  the  pori  biliarii 
are  enlarged  at  their  free  extremities  so  as  to  be  there  like  a pin  at 
its  head,  in  a manner  so  common  in  glandular  structure.  Krause 
asserts  the  fact,  and  states  that  the  enlargement  measures  from  to 
of  an  English  line,  and  there  are  said  to  be  preparations  of 
the  kind  in  Utrecht. f It  is  asserted  that  a fine  injection  passes 
more  readily  from  them  into  the  lymphatics  than  into  any  other 
order  of  vessels;  which  may  account  for  the  promptitude  of  jaundice 
upon  an  obstruction  of  the  hepatic  duct.  The  most  minute  branches 

* Husohke  ut  supr.  p.  124. 

f Muller,  Phys.,  p.  491.  London,  1840. 


THE  LIVER. 


73 


of  the  biliary  ducts  in  the  acini  are  so  close  together  that  they  seem 
to  be  united  to  one  another,  Their  diameter,  according  to  Midler, 
varies  from  to  is  of  an  English  inch ; they  are,  therefore,  much 
larger  than  the  finest  capillary  blood  vessels. 

A case  of  obstruction  of  the  hepatic  duct  by  a medullary  mass,  in 
the  practice  of  Professor  Geddings  of  South  Carolina,  in  arresting 
the  bile  produced  a distention  of  the  extreme  biliary  canaliculi, 
which  were  observed  by  him  to  commence  in  cceca  closely  impacted 
one  against  another.* 

The  Venaj  Portarum  having  arisen  from  the  junction  of  all  the 
veins  of  the  stomach,  intestines,  pancreas  and  spleen,  is  about  three 
inches  in  length  when  it  reaches  the  transverse  fissure,  of  the  liver  by 
going  over  the  duodenum  and  under  the  pancreas.  It  immediately 
divides  into  two  branches,  called  collectively  the  Sinus  Venae  Por- 
tarum, which  is  at  right  angles  with  the  trunk  of  the  vein.  The  right 
branch  being  the  shortest  and  largest,  is  distributed  by  radiating 
trunks  to  the  right  lobe  of  the  liver ; the  left  branch  is  distributed, 
after  the  same  manner,  to  the  left  lobe,  to  the  lobulus  Spigelii,  and 
to  the  lobulus  quartus.  Some  of  its  branches  anastomose  with  the 
hepatic  veins,  which  accounts  for  the  ease  with  which  an  injection 
will  pass  from  one  to  the  other. 

The  vena  portarum  is  finally  reduced  into  extremely  attenuated  ca- 
pillary extremities,  whose  diameter  is  from  to  tW  of  a line  in 
diameter  according  to  Weber.  They  invest  the  acini,  penetrate 
them  to  some  extent,  and  anastomose  freely  together  in  observing 
this  arrangement.  Their  meshes  are  occupied  according  to  Weber 
almost  wholly  by  the  biliary  canaliculi,  but  just  doubts  are  now  en- 
tertained whether  they  do  more  than  come  in  contact  with  them, 
contrary  to  an  opinion  formerly  held  that  they  discharge  into  or  anas- 
tomose with  them.  Their  final  termination  is  in  the  corresponding 
branches  of  the  Hepatic  veins,  the  freedom  of  which  communication 
there  is  no  difficulty  in  proving  by  injection  as  well  as  by  the  ordinary 
laws  of  the  circulation  of  the  blood. 

The  Hepatic  Artery  is  a branch  of  the  coeliac,  and  in  approaching 
the  transverse  fissure  divides  into  three  or  more  branches,  that  pene- 
trate the  substance  of  the  liver,  between  the  sinus  venae  portarum 
and  the  ducts  as  they  come  out ; one  branch  goes  to  the  right  lobe, 

* North  Am.  Journ.  1835. 

| Anat.  Atlas,  Fig.  350. 


74 


ORGANS  OF  DIGESTION. 


another  to  the  left,  and  a third  to  the  lobulus  Spigelii.  There  is 
some  variety  in  regard  to  the  precise  mode  of  distribution ; and  their 
division  into  subordinate  ramifications  frequently  occurs,  before  they 
get  fairly  into  the  substance  of  the  liver.  When  there,  they  seem 
to  be  intended  for  the  nourishment  of  this  organ,  and  follow  the 
ramifications  of  the  vena  portarum  and  of  the  biliary  ducts,  forming 
upon  them  a very  delicate  and  complicated  tissue  of  anastomosing 
vessels ; some  of  which,  probably  the  vasa  vasorum,  communicate 
with  the  vena  portarum. 

The  hepatic  artery  having  been  reduced  into  extremely  fine 
branches  is  found  expending  itself  upon  the  walls  of  the  vena  por- 
tarum and  of  the  biliary  ducts  ; it  must  of  course,  supply  itself  with 
nourishing  blood,  and  also  the  parenchyma  of  the  liver;  and  it  finally 
makes  a plexus  in  the  case  of  each  acinus  intimately  blended  with 
the  ultimate  plexus  of  the  vena-portarum,  with  which  it  has  a free 
communication  as  readily  proved  by  injection.  There  ought  to  be 
but  little  doubt  that  the  vena  portarum  is  the  primary  recipient  of  its 
blood.  The  analogy  is  established  in  the  gall  bladder,  where  the  cystic 
artery  discharges  into  the  cystic  vein : the  latter  then  proceeding  to 
the  vena  portarum,  is  sufficient  proof  of  the  compatibility  of  this  ar- 
rangement. The  venous  vasa  vasorum  of  the  vena  portarum  is  also 
in  favour  of  it.  But  whether  such  termination  is  exclusively  in  the 
vena  portarum  may  give  rise  to  a question. 

Many  of  the  finer  branches  of  this  artery  ( Rami  serosi)  reach  from 
the  interior  to  the  surface  of  the  liver,  and  running  out  a great  length 
with  almost  uniform  size  make,  under  the  peritoneal  coat,  a most 
beautiful  and  exquisite  reticulation  by  their  own  branches,  and  those 
of  adjoining  vessels  of  the  same  kind.  A reticulation  so  fine  that  it 
strongly  resembles  a lymphatic  one. 

The  Hepatic  Veins  arise  in  the  acini  from  the  capillary  termina- 
tion of  the  vena  portarum  and  the  hepatic  artery.  Their  branches 
are  successively  accumulated  into  three  large  trunks,  the  collective 
area  of  which  vastly  exceeds  that  of  the  vessels  bringing  the  blood  to 
the  liver.  Two  of  these  trunks  come  from  the  right  lobe  and  one 
from  the  left,  to  empty  into  the  ascending  cava,  while  it  is  still  in 
contact  with  the  liver,  immediately  below  the  diaphragm ; just  below 
the  preceding  trunks  there  are  five  or  six,  sometimes  more,  small 
hepatic  veins,  coming  from  the  posterior  margin  of  the  liver,  and 
from  the  lobulus  Spigelii.  The  hepatic  veins  are  destitute  of  valves, 
and  remarkable  for  the  thinness  of  their  parietes.  An  injection  passes 


THE  LIVER. 


75 


readily  from  them  into  the  other  systems  of  vessels.  They  may  be 
recognised  by  their  insulated  course,  and  by  their  consisting  in  trunks 
which  converge  from  the  periphery  of  the  liver  to  the  vena  cava,  while 
all  the  other  vessels  diverge  from  the  transverse  fissure  to  the  peri- 
phery, and  consequently  cross  the  course  of  the  hepatic  veins. 

The  larger  branches  of  the  venae  hepaticse  exhibits  a remarkable 
number  of  very  small  branches  with  patulous  mouths  a sixth  of  a line 
or  less  in  their  diameter,  which  come  directly  from  the  contiguous 
acini;  having  arisen  by  still  smaller  extremities  in  connexion  with 
the  capillary  terminations  of  the  other  blood  vessels  of  the  liver. 
The  number  of  such  foramina  gives  to  the  sides  of  the  hepatic  veins 
a cribriform  appearance.  The  branches  of  the  hepatic  veins  seem 
to  free  themselves  more  completely  from  their  entanglement  with 
the  other  vessels  near  the  centre  of  the  acinus,  and  then  pursue  a 
course  to  themselves  not  difficult  to  follow  out. 

Owing  to  the  involution  of  one  set  of  the  hepatic  capillaries  with 
another,  there  is  an  essential  and  almost  insurmountable  difficulty  in 
forming  a conception,  or  making  a preparation  which  will  elucidate 
their  ultimate  arrangement.  In  explanation  of  this  difficulty  Mul- 
ler considers  that  there  is  an  ulterior  plexus  of  capillary  blood 
vessels  with  which  the  other  three  communicate  freely,  this  is  pro- 
bably the  fact,  including  the  lymphatic  system  also;  but  the  precise 
mode  of  its  formation  is  as  yet  not  ascertained,  an  idea  long  ago  ad- 
vanced by  Chaussier  in  regard  to  all  glandular  structures. 

According  to  the  valuable  observations  of  Mr.  Kiernan,*  the  acini 
of  Malpighi  should  be  called  lobules,  inasmuch  as  they  consist  in  the 
collection  of  smaller  granulated  bodies,  to  which  he  restricts  the 
name  of  acini.  The  objection  to  this  principally  is  that  it  intro- 
duces a new  definition,  on  a point  heretofore  considered  as  settled  in 
the  universal  phraseology  of  anatomists. 

His  statement  then  is  that  the  finer  branches  of  the  vena  portarum, 
which  he  calls  Interlobular  veins,  make  a perfect  and  minute  plexus 
surrounding  the  lobules  or  small  granular  masses  of  the  liver ; they 
then  form  convergent  lines  of  vessels  directed  towards  the  centre  of 
each  lobule  and  communicating  by  transverse  branches  with  one 
another.  These  latter  connexions  or  the  sets  of  veins  making  them, 
constitute  the  lobular  venous  plexus,  and  in  their  intervals  are  placed 
what  he  calls  the  acini  or  subordinate  granules. 

He  says,  also,  that  the  Hepatic  Duct  forms  a plexus  upon  the 

* Anat.  and  Physiol,  of  Liver,  Phil.  Trans.  London,  1833. 


76 


ORGANS  OF  DIGESTION. 


lobules  like  that  of  the  vena  portarum  ; the  plexuses  of  the  contigu- 
ous lobules  being  indisposed  to  anastomose,  though  he  thinks  there 
is  ground  to  believe  in  such  anastomosis.  The  interlobular  biliary 
ducts  then  penetrate  the  lobule  and  ramify  by  anastomotic  connex- 
ions through  it.* 

The  Hepatic  Artery,  he  says,  makes  also  a plexus  upon  the  surface 
of  the  lobule,  and  penetrates  interiorly  from  its  periphery  towards 
the  centre,  to  end  in  the  vena  portarum.  Meckel  says,  that  they  end 
in  the  incipient  branches  of  the  venae  hepaticae. 

The  Hepatic  veins,  according  to  Mr.  Kiernan,  are  seen  as  a small 
trunk  in  the  centre  of  a lobule;  this  trunk  arises  from  the  conver- 
gence of  from  four  to  eight  venules,  from  the  periphery  to  the  cen- 
tre of  the  lobule. 

It  is  stated  by  Mr.  Kiernan,  that  the  elements  of  the  above  ar- 
rangement of  ducts  and  blood  vessels  are  formed  very  distinctly  in 
the  left  lateral  ligament  of  the  liver. 

He  appears  not  to  have  succeeded  in  injecting  the  hepatic  veins 
from  the  hepatic  artery,  though  he  can  inject  them  from  the  vena 
portarum.  His  injection  was  probably  not  fine  enough,  as  there 
is  not  the  slightest  difficulty  in  filling  all  the  ducts  and  blood  ves- 
sels of  the  liver  from  either  set,  provided  one  throws  in  a very  fluid 
injection  ; the  use  of  water  simply  will  prove  this  beyond  doubt. 

Mr.  Kiernan’s  statements  appear  to  have  been  received  as  decisive 
by  his  countrymen,  both  anatomists  and  physiologists,  and  by  some 
of  the  continental  anatomists;  generally,  without  much  apparent  ex- 
amination for  themselves.  In  some  respects  he  has,  judging  from 
his  figures,  been  peculiarly  fortunate  by  finding  in  his  dissections  the 
lines  of  blood  vessels  upon  the  same  plane  and  so  clear;  when  their 
general  course,  according  to  common  experience,  is  so  tortuous,  un- 
even, and  implicated. 

A greater  reserve  has  been  manifested  by  the  German  teachers, 
thus  there  is  a remarkable  discordance  between  his  observations  on 
the  incipient  state  of  the  biliary  pores,  and  Krause’s  and  Huschke’s, 
the  latter  speaks  pointedly  of  the  ideal  figure  of  Kiernan.  Wagner, 

* According  also,  to  Weber  and  Kroninberg,  the  incipient  extremities  of 
the  biliary  ducts  make  a net-work  in  the  acini.  Weber  says,  that  the  diame- 
ter of  these  branches,  is  from  the  1-1340  to  the  1-900  of -an  inch.  That  the 
blood  capillaries  have  a diameter  of  from  the  1-1959  to  the  1-1463  of  an  inch, 
and  that  the  distance  passed  by  the  blood  from  the  smallest  portal,  to  the 
smallest  hepatic  vein  is  from  the  1-80  to  the  1-70  of  an  inch.  Muller’s  Arch. 
4184. 


THE  LIVER. 


77 


of  accomplished  skill  as  an  anatomist,  in  admitting  that  angular  cells 
form  the  lobules,  {acini)  and  that  these  are  separated,  one  from 
the  other,  by  cellular  substance,  asserts  cc  that  he  finds  it  much  more 
difficult  to  say  how  the  different  vessels — the  last  divisions  of  the 
vena  portae,  of  the  venae  hepaticae,  and  of  the  ductus  hepaticus  com- 
port themselves  in  the  interior  of  the  lobules.  I regard  the  beautiful 
figures  and  the  descriptions  of  Mr.  Kiernan,  as  the  best  and  most 
accurate  that  have  been  published,  although  they  very  certainly  also 
include  many  mistakes.”* 

At  the  bottom  of  tlje  transverse  fissure  of  the 
liver  is  to  be  found  a dense  cellular  fibrous  tissue, 
which  invests  the  vena  portarum,  the  hepatic  artery, 
and  the  biliary  ducts  ; and,  as  they  all  keep  together 
in  their  ramifications,  this  tissue  follows  them 
throughout  the  substance  of  the  liver,  and  thereby 
forms  sheaths  for  them.  It  may  be  considered  as 
continuous  with  the  processes  sent  in  from  the  cel- 
lular coat ; and,  contrary  to  the  opinion  of  Glisson, 
whose  capsule  it  has  been  called,  it  is  devoid  of 
muscular  structure. 

The  lymphatics  of  the  Liver  are  large,  numerous,  and  deprived 
of  valves,  hence  they  can  be  readily  injected  and  make  a brilliant 
close  plexus  on  its  surface,  from  which  mercury  soon  subsides  owing 
to  the  freedom  of  their  communication  with  the  deeper  lymphatics. 
They  leave  it  by  various  routes  in  large  trunks  which  ascend  and 
depart  by  the  several  ligaments. 

The  nerves  of  the  liver  are  branches  of  the  solar  plexus  of  the 
sympathetic,  and  reach  it  through  the  transverse  fissure  in  com- 
pany with  the  blood  vesels. 

The  liver  appears  in  the  embryo  to  be  originally  formed  by  a 
protrusion  of  the  walls  of  a part  of  the  intestinal  canal  ;f  the  lungs 
and  pancreas  present  a similar  mode  of  evolution. 


Fig.  28. 


Secreting  cells 
of  the  Human 
Liver;  z,  nucleus; 
b,  nucleolus ; c, 
oil-particles. 


Of  the  Gall-Bladder 

The  Gall-Bladder  ( Cystis  Fellea)  is  a reservoir  for  the  bile,  secreted 
by  the  liver.  It  is  fixed  on  the  under  surface  of  the  great  lobe,  to 

* Elements  of  Physiol;  London,  1842. 
f Muller,  loc.  cit,  p.  490. 
j:  Anat.  Atlas.  Figs.  348,  349. 


Vol.  II.— 8 


78 


ORGANS  OF  DIGESTION. 


the  right  of  the  umbilical  fissure,  and  removed  from  the  latter  by 
the  lobulus  quartus.*  It  is  an  oblong  pyriform  sac,  having  its 
anterior  extremity  or  fundus  projecting  somewhat  beyond  the  an- 
terior margin  of  the  liver,  while  the  posterior  end  reaches  to  the 
transverse  fissure.  Its  long  diameter  inclines  slightly  to  the  right 
side,  so  that  it  is  not  precisely  in  an  antero-posterior  line.  It  varies 
in  its  shape  in  different  subjects,  being  much  more  spheroidal  in 
some  than  in  others.  Its  fundus  is  rounded  and  obtuse,  while  the 
posterior  end  is  gradually  reduced  to  a narrow  neck,  which  is  bent 
upon  itself,  so  as  to  retard  the  flow  of  a (lui^  through  it.  Its  upper 
surface  is  in  contact  with  the  substance  of  the  liver,  and  is  received 
into  a broad  shallow  fossa,  while  the  lower  surface  is  projecting, 
and  by  coming  in  contact  with  the  transverse  colon,  tinges  it  with 
bile,  by  transudation  after  death. 

The  Gall-Bladder  has  three  coats,  a peritoneal,  a cellular,  and  a 
mucous  one. 

The  Peritoneal  Coat  is  not  complete,  but  only  covers  that  part  of 
the  sac  not  received  into  the  fossa  on  the  under  surface  of  the  liver; 
it  is,  therefore,  a continuation  of  the  peritoneal  coat  of  the  latter; 
sometimes,  however,  the  gall-bladder  is  so  loosely  attached  to  the 
liver  that  it  almost  hangs  off  from  it,  in  which  case  the  peritoneal 
coat  is  nearly  complete. 

The  Second  coat  is  condensed  cellular  membrane,  ( Tunica  Pro- 
pria.) Through  it  ramifies  a great  number  of  lymphatics,  and  blood 
vessels;  below,  it  attaches  the  peritoneal  to  the  mucous  coat,  and 
above,  the  latter  to  the  liver. 

The  Mucous  Coat  is  always  tinged  of  a deep  green  or  yellow,  by 
the  bile  which  it  contains  percolating  after  death  ; for  it  is  said  to  be, 
before  that,  of  a light  colour.  This  coat  is  thrown  into  irregular 
tortuous  folds  or  wrinkles  of  extreme  delicacy,  in  the  intervals  of 
which  are  many  round  or  polyhedrous  cells,  causing  it  to  look,  when 
floated  in  water,  like  a fine  honeycomb:  such  as  are  about  the 
fundus  of  the  sac  are  superficial,  and  not  so  distinct;  but  those  near 
its  middle  and  about  the  neck,  are  a line  or  a line  and  a half  deep. 
In  the  neck  or  apex,  and  in  the  beginning  of  the  cystic  duct,  are 
from  three  to  seven,  sometimes  twelve  semilunar  duplicatures  of 
the  internal  membrane,  which  also  retard  the  flux  and  afflux  of  any 

* I have  seen  an  instance  where  it  was  to  the  left  of  the  umbilical  fissure, 
on  the  small  lobe.  The  latter  was  much  longer  than  common.  Dec.  1830. 


THE  LIVER. 


79 


fluid,  though  they  do  not  afford  so  much  resistance  to  the  ingress  as 
to  the  egress  of  it.  These  duplicatures  are  sometimes  partially  ar- 
ranged into  a spiral  valve,  projecting  from  the  inside  of  the  duct,  and 
forming  two  or  three  turns.*  Very  small  mucous  follicles  exist  over 
the  internal  face  of  this  membrane,  the  discharge  of  which  fills  the 
gall-bladder  when  the  secretion  of  bile  has  been  interrupted  by  dis- 
eased action,  as  in  yellow  fever,  or  by  scirrhus  of  the  liver. 

The  artery  of  the  gall-bladder  is  a branch  of  the  hepatic.  Its 
veins  empty  into  the  vena  portarum.  Its  nerves  come  from  the 
sympathetic,  and  its  lymphatics  join  those  of  the  liver. 

The  gall-bladder  is  developed  as  a diverticulum,  from  the  Hepatic 
Duct. 


Of  the  Bile  Buds. 

A succession  of  very  fine  branches  having  arisen  from  the  acini 
of  the  liver,  these  branches  are  united  into  three  or  four  trunks  by 
the  time  they  reach  the  transverse  fissure.  The  trunks  then  coalesce 
into  a single  Duct,  the  Hepatic,  of  eighteen  or  twenty  lines  in  length, 
and  about  the  diameter  of  a writing-quill.  The  Hepatic  Duct  is  then 
joined  at  a very  acute  angle  with  the  Cystic  duct  or  that  from  the 
gall-bladder,  which  is  somewhat  shorter  and  smaller;  the  union  of 
the  two  forms  the  Common  Duct,  ( Dudus  Communis  Choledochus.) 
The  latter  is  larger  than  either  of  the  others  singly,  and  is  three  or 
three  and  a half  inches  long ; it  descends  behind  the  right  extremity  of 
the  pancreas  through  its  substance,  passes  nearly  an  inch,  obliquely, 
between  the  coats  of  the  duodenum,  becoming  at  the  same  time 
diminished  in  diameter;  and,  finally,  ends  by  an  orifice  still  more 
contracted,  on  the  internal  face  of  this  gut,  at  its  second  turn,  and 
about  three  or  four  inches  from  the  stomach.  The  orifice  is  marked 
by  a small  surrounding  tubercle  somewhat  obscured  by  the  valvuke 
conniventes. 

The  Hepatic,  the  Cystic,  and  the  Common  Duct  are  situated,  as 
mentioned,  along  the  right  margin  of  the  lesser  omentum,  and  have 
the  vena  portarum  and  the  hepatic  artery  to  their  left. 

The  bile  ducts  are  formed  by  two  coats  ; the  external  is  a fibrous, 

* Discovered  by  M.  Amussat,  of  Paris.  He  has  also  detected  muscular 
fibres  in  the  gall-bladder  and  biliary  ducts,  in  which  we  see  an  analogy  with 
other  hollow  viscera. — Am.  Jour.  Med.  Sciences,  Vol.  ii.  p.  193. 


SO 


ORGANS  OF  DIGESTION. 


lamellated,  and  very  extensible  membrane,  while  the  internal  is 
mucous,  having  the  same  structure  with  that  of  the  gall-bladder,  of 
which  it  is  in  direct  continuation.  In  the  Cystic  Duct,  and  at  the 
lower  part  of  the  Common  Duct  are  several  longitudinal  folds.  The 
Common  Duct  sometimes  receives,  just  before  it  empties  into  the 
duodenum,  the  Pancreatic  Duct. 


Of  the  Bile. 

This  secretion  from  the  liver,  is  of  a deep  yellow,  sometimes 
green  colour  : when  recent,  it  is  thin  and  fluid ; but  after  it  has  been 
conveyed  to  the  gall-bladder,  and  permitted  to  remain  there  for 
some  time,  it  becomes  as  thick  as  molasses,  and  increases  also  in 
the  intensity  of  its  colour  and  in  bitterness.  Some  anatomists  have 
believed  that  there  was  a more  direct  communication  between  the 
liver  and  the  gall-bladder  than  that  through  the  hepatic  and  the 
cystic  duct ; but  repeated  and  close  observations  have  proved  the 
opinion  to  be  erroneous,  or  at  least  destitute  of  proper  proof : it  is 
therefore,  clear,  that  the  difference  between  the  hepatic  and  the 
cystic  bile,  depends  upon  the  watery  particles  being  removed  from 
the  latter  by  the  absorbing  power  of  the  internal  coat  of  the  gall- 
bladder. 

According  to  Berzelius,  the  chemical  analysis  of  bile  furnishes 
about  eighty  parts  of  water,  eight  of  a particular  substance,  Biline, 
which  assumes  a resinous  condition  on  the  application  of  an  acid: 
three  of  mucus ; and  nine  of  saline  matters  ; of  which  soda  is  a 
principal  constituent. 


SECT.  II. — OP  THE  SPLEEN.* 

The  Spleen,  [Lien,  Splen ,)  is  situated  deeply  in  the  posterior  part 
of  the  left  hypochondriac  region,  and  is  bounded  above  by  the  dia- 
phragm, below  by  the  colon,  and  on  the  right  by  the  great  end  of 
the  stomach,  and  by  the  pancreas.  It  is  not  ascertained  that  it 
secretes  any  thing. 

Its  colour  varies  from  a deep  blue  to  a dark  brown.  In  shape 
it  resembles  the  longitudinal  section  of  an  oval,  being  flat  or  very 

* Anat.  Atlas,  Figs.  351  to  354,  inclusive.. 


THE  LIVEH. 


81 


slightly  concave  on  the  surface  next  to  the  stomach,  and  convex  on 
that  contiguous  to  the  diaphragm.  Occasionally  its  margins  are 
notched,  but  this  is  not  invariably  the  case.  Its  flat  surface  is 
slightly  depressed  longitudinally  in  the  centre ; into  a fissure  which 
is  imperfect,  and  where  the  blood  vessels  enter  into  it,  by  six  or 
eight  foramina. 

Several  spleens  sometimes  exist  in  the  same  individual,  in  wThich 
case  the  supernumerary  ones  are  not  larger  than  nutmegs.  The 
common  size  of  this  organ  is  about  four  and  a-half  inches  long,  by 
two  and  a-half  or  three  wide,  in  wdiich  case  it  has  a solid  firm  feel ; 
but  it  very  often  exceeds  these  dimensions ; its  transition  and  va- 
rieties of  magnitude  are  so  frequent,  that  no  settled  rule  can  be 
established.  In  its  inordinate  enlargements  I have  seen  it  only  a 
little  smaller  than  the  liver ; its  texture  in  this  case  is  soft  and  easily 
lacerated. 

It  is  fixed  in  its  place  by  three  lines  of  reflection  or  processes 
of  peritoneum,  called  ligaments,  whose  names  indicate  their  places 
of  attachment.  They  are  the  Gastro-Splenic  Ligament  or  Omen- 
tum, which  passes  from  the  stomach  to  the  spleen,  and  in  which 
are  the  vasa  brevia  of  the  stomach : the  Splenico-Phrenic  Liga- 
ment, which  goes  from  the  spleen  to  the  diaphragm,  attaching  itself 
to  the  latter  at  the  left  of  the  oesophageal  foramen,  and  then  descending 
along  the  posterior  internal  face  of  the  spleen,  in  a line,  behind  the 
gastro-splenic  ligament:  and  the  Splenico-Colic  Ligament,  which 
passes  from  the  spleen  to  the  colon,  being,  as  it  were,  a process  from 
the  left  extremity  of  the  gastro-colic  omentum.  These  reflections, 
by  being  continued  over  the  spleen,  give  it  a complete  peritoneal 
coat,  which  is  raised  up  with  more  difficulty  than  the  corresponding 
membrane  of  any  other  viscus  of  the  abdomen,  and  is  cominonlv 
thrown  into  very  small  inequalities  or  wrinkles. 

The  internal  or  proper  coat  of  the  spleen  is  a grayish,  compact, 
extensible,  and  elastic  membrane,  the  use  of  which  is  evidently  to 
sustain  the  natural  shape  of  the  organ,  and  to  support  its  parenchy- 
matous structure.  It  sends  in  processes  to  accompany  the  blood 
vessels  (capsulae  Malpighii)  and  from  its  internal  face  there  proceeds 
a multitude  of  lamellae  and  of  fibres,  which  traverse  its  cavity  in 
every  direction,  and  reduce  it  into  a cellular  condition,  not  unlike 
the  cavernous  structure  of  the  penis. 

Of  the  Intimate  Structure  of  the  Spleen. — The  spleen,  in  propor-. 
tion  to  its  size,  is  furnished  to  a remarkable  degree  with  blood.  The 

8 * 


82 


ORGANS  OF  DIGESTION, 


largest  branch  of  the  eoeliac  artery  runs  to  it  along  the  superior  mar- 
gin of  the  pancreas,  forming  numerous  serpentine  flexures,  and  dis- 
tinguished for  its  thickness  and  size  ; it  divides  into  several  trunks 
before  penetrating  into  the  spleen,  and  enters  by  the  foramina  in  the 
fissure.  The  veins  come  out  by  a number  of  trunks  equal  to  what 
the  artery  is  divided  into  ; they  assemble  then  into  a single  trunk, 
which  attends  the  artery  along  the  pancreas,  is  destitute  of  valves, 
and  empties  into  the  vena  portarum. 

The  Splenic  artery  having  penetrated  into  this  organ,  is  divided 
and  subdivided  into  a radiating  succession  of  very  fine  branches, 
which,  according  to  the  injections  of  Ruysc.h,  do  not  anastomose 
with  each  other ; in  consequence  of  which  one  part  is  sometimes 
finely  injected  and  not  another.  This  corresponds  with  my  own  ob- 
servations. The  veins,  on  the  contrary,  do  anastomose,  not  only  as 
regards  the  collateral  branches  of  the  same  primitive  trunk,  but  also 
by  the  collateral  branches  of  different  trunks.  These  anastomoses 
are  not  large.  The  veins  of  the  spleen  are  remarkable  for  the  tenuity 
of  their  coats,  and  for  the  great  disproportion  of  their  area,  with  that 
of  the  arteries,  which  in  the  larger  trunks  is  rated  at  five  to  one,  and 
in  the  smaller  at  twenty  to  one.  The  larger  veins  look  cribriform 
when  viewed  from  their  interior,  owing  to  the  number  of  fine  branches 
which  they  receive. 

The  veins  of  the  spleen,  in  their  ramifications  through  this  organ, 
besides  their  frequent  anastomoses,  undergo  sinus-like  enlargements, 
approaching  the  structure  of  the  corpus  cavernosum  penis,  and  their 
walls  are  formed  merely  from  the  internal  venous  coat.  The  ar- 
teries terminate  freely  in  the  veins,  as  may  be  proved  by  fine  injec- 
tions, and  by  the  microscope. 

The  mass  of  the  spleen  upon  superficial  examination,  seems  to 
consist  in  a dark  brown  bloody  pulp,  (Substantia  rubra)  which  is 
contained  in  the  cells  dividing  the  cavity  of  the  internal  coat,  and 
may  be  easily  demonstrated  by  tearing  or  cutting  the  spleen,  and 
scraping  it  with  a knife  handle. 

The  pulpy  substance  of  the  spleen  under  the  microscope,  is  com- 
posed of  small  spheroid  or  oval  granules  of  a reddish  brown  colour, 
and  about  the  size  of  the  globules  of  the  blood.  According  to  Mr. 
Gulliver,*  they  are  more  unequal  in  size  than  the  blood  discs,  their 
diameter,  varying  from  1-6000  to  1-1777  of  an  inch,  and  they  are 


* Gerber’s  Gent.  Anat.  p.  102.. 


TOT  SPLEEN 


83 


found  in  blood  taken  from  the  splenic  vein.  They  are  easily  sepa- 
rated from  one  another. 

The  minute  arteries  of  the  spleen  ramify  in  tufts  among  their  gra- 
nules, and  then  terminate  in  a plexus  of  venous  canals  whose  walls 
are  so  thin  that  the  veins  appear  as  mere  channels  in  the  pulp. 

A question  has  arisen  whether  the  pulp  (substantia  rubra)  be  extrava- 
sated  in  the  cells  which  contain  it,  or  whether  it  be  still  retained  in  the 
extremities  of  the  blood  vessels.  Superficial  examination  is  in  favour 
of  the  first,  but  M.  Marjolin  denies  it  on  the  following  grounds;  that 
injections,  cautiously  made,  pass  immediately  from  the  arteries  into 
the  veins  ; and  that  the  spleen,  wrhen  successfully  injected  and  frozen 
does  not  exhibit  ice  in  the  interstices  of  its  vessels,  while  their  capil- 
lary ramifications  distended  by  the  injected  fluid,  are  distinctly  seen. 
From  these  facts  he  concludes  that  the  glandular  structure  of  the 
spleen  is  formed  essentially  of  arterial  and  venous  capillary  vessels 
with  very  delicate  and  extensible  coats ; that  they  communicate  with 
one  another  without  the  intermedium  of  any  cell ; and  that  the 
extreme  tenuity  of  these  vessels,  and  their  extensibility  in  every  di- 
rection, are  sufficient  to  explain  the  augmentation  of  volume  of  the 
spleen,  under  certain  circumstances,  as  well  as  the  promptitude  of 
its  diminution  under  others. 

MM.  Assolant  and  Meckel  believe  that  blood  besides  being  in 
the  arteries  and  veins,  is  placed  in  a state  of  particular  combination 
and  of  intimate  union  with  the  other  organic  elements  of  this  viscus, 
and  with  a large  quantity  of  albumen ; and  that  this  combination  of 
the  blood  forms  the  dark  brown  pulp  alluded  to.  The  great  quan- 
tity of  albumen  in  the  pulp,  is  readily  proved  by  the  hard  coagulum 
which  it  forms,  when  steeped  in  alcohol. 

In  addition  to  this  pulp,  many  observers  have  met  in  the  spleen 
with  an  abundance  of  rounded  corpuscles,  (Corpuscula  Malpighii,) 
varying  in  size  from  an  almost  imperceptible  magnitude  to  a line  or 
more  in  diameter.*  They  are  of  a gelatinous  consistence,  soft, 
grayish,  and  semi-transparent,  and  either  cluster  together,  or  are 
widely  separated  and  have  a diameter  of  from  one-sixth  to  a third  of 
a line.  Their  exact  structure  is  undetermined.  By  Malpighi,  they 
were  considered  glandular,  and  by  Ruysch,f  as  convoluted  vessels. 
Professor  Soemmering  from  the  following  paragraph,  seems  to  join 

* Malpighi,  Ruysch,  Hewson,  Home,  Dupuytren,  Meckel,  &c. 
f Epis.  Anat.  IV. 


84 


ORGANS  OF  DIGESTION. 


in  the  opinion  of  the  latter  : “ Qui  nonnunquam  occurrunt,  acini  vel 
glomeruli,  microscopii  ope  accuratissime  explorati,  nihil  sunt  nisi 
vasorum  fasciculi,  vel  teretes  penicilli  aut  cirri  vasculosi.”  Accord- 
ing to  the  observations  of  Sir  Everard  Home,  they  swell  consider- 
ably after  an  animal  has  finished  drinking. 

The  corpuscles  are  seen  with  difficulty  in  the  human  spleen,  in 
animals  they  are  much  more  distinct,  as  in  the  hog,  sheep,  and  ox. 
Muller*  admits  their  connexion  with  the  arteries,  but  is  inclined  to 
consider  them  as  excrescences  from  their  coats,  as  in  his  injections 
the  arteries  were  seen  to  pass  through,  but  not  to  ramify  in  them. 

Their  real  existence  has  been  much  contested,  owing  to  the  un- 
certainty of  finding  them,  but  it  now  seems  to  be  admitted,  that  the 
best  spleens  for  this  purpose  are  such  as  are  perfectly  healthy,  and 
taken  from  subjects  who  have  died  suddenly.  A little  delay  dis- 
poses them  to  become  putrescent,  and  more  pulpy,  as  it  does  the 
red  substance  of  this  organ.  Those  of  a brownish  red  are  best 
suited  for  the  investigation. 

The  corpuscles  of  Malpighi  are  at  least  vesicles,  with  very  thin 
parietes,  hence  when  punctured,  their  fluid  which  is  found  of  an  al- 
buminous character,  escapes,  and  they  collapse.  They  are  some- 
times in  a group  of  six,  suspended  to  an  arterial  ramuscule  like  a 
pedicle.  The  vessels  do  not  penetrate  them  but  are  confined  to 
their  exterior,  where  they  form  a very  fine  net-work.  The  fluid 
which  they  contain,  is  according  to  Bischoff  and  Huschke,  white, 
with  a multitude  of  globules  swimming  in  it,  and  looking  very  much 
like  chyle.  Huschke  after  much  inquiry  into  their  structure,  considers 
it  most  probable  that  they  are  dilatations  of  the  lymphatic  vessels  of 
the  spleen,  from  their  analogy  with  the  interior  of  a splenic  or  me- 
senteric lymphatie  gland  of  an  infant;  and  he  thinks  all  that  remains 
to  verify  the  conjecture  is  an  obvious  connexion  with  some  lymphatic 
vessels,  afferent  and  efferent.  By  Simon  they  are  considered  as 
aggregations  of  Cytoblasts.f 

The  spleen  has  many  lymphatic  vessels;  and  is  furnished  with 
nerves  from  the  solar  plexus. 

The  spleen,  from  having  no  excretory  duct,  and  consequently,  from 
our  inability  to  ascertain  whether  it  secretes,  has  its  uses  unknown. 
No  single  theory  concerning  it  has  ever  been  generally  adopted,  for 
speculations  have  multiplied  in  proportion  to  the  obscurity  of  the 


Physiol,  p.  618.  f Brit,  and  For.  Med.  Rev.  p.  567.  April,  1816. 


THE  SPLEEN. 


85 


subject.  By  some  it  is  thought  to  exercise  merely  a mechanical 
function— by  others,  a chemical  one' — by  others,  a dynamic — and 
in  the  midst  of  such  uncertainty,  some  have  concluded  that  it 
had  no  special  function.  The  hypothesis  which  to  me  is  most 
reasonable,  is,  that  of  its  acting  a subsidiary  part  to  the  liver.  It 
would  seem,  indeed,  as  a general  rule  in  regard  to  glandular  struc- 
tures and  such  other  highly  vascular  organs  of  the  body  as  have  an 
intermittent  function,  that  the  blood  which  is  sent  to  them  during 
their  state  of  activity,  should  be  passed  off  through  a different 
channel,  while  they  are  in  a state  of  repose.  This  does  a double 
service,  it  prevents  superfluous  secretion,  and  it  also  keeps  up  the 
vascular  equilibrium  of  the  body;  as  there  must  be  always  in  readi- 
ness a quantity  of  blood  sufficient  for  the  supply  of  any  secretion 
which  may  be  wanted  for  the  time. 

This  proposition  will  derive  some  additional  illustrations  from  the 
foetal  state.  The  kidneys  being  then  inactive  the  capsulse  renales 
take  off  their  blood,  and  thereby  prevent  w’hat  would  otherwise  be 
a very  inconvenient  secretion  of  urine;  again,  the  lungs  being  also 
then  inactive,  the  circulation  through  them  is  proportionately  re- 
duced, and  the  superabundant  blood  is  conducted  through  the  thy- 
mus gland.  But  as  the  full  functions  of  the  lungs  and  of  the  kidneys 
are  established  upon  birth,  and  continue  uninterrupted  during  life  ; 
their  supplementary  organs  respectively,  as  the  thymus  gland,  and 
the  capsulae  renales,  not  being  wanted ; wither  away  after  the  early- 
period  of  infantile  existence  is  passed. 

In  regard  to  the  liver,  its  functions  also  suspended  during  the 
fcetal  state,  are  of  an  intermittent  kind  throughout  life,  the  spleen 
may,  therefore,  be  considered  a vicarious  organ  for  it,  during  the 
whole  period  of  existence;  receiving  its  blood  during  the  continua- 
tion of  uterine  life,  and  in  the  intermission  of  action,  during  common 
life.  The  spleen  is,  therefore,  an  organ  useful  to  the  fcetal  and  to 
the  perfect  state,  and  we,  consequently,  never  see  it  in  the  collapsed 
and  effete  condition  of  the  thymus  gland,  and  renal  capsules. 

The  same  reasoning  which  applies  to  the  spleen,  will  also  apply 
to  the  Thyroid  Gland  : the  latter  may  be  considered  as  executing  for 
the  salivary  glands  during  foetal  and  perfect  existence,  what  the 
spleen  does  for  the  liver.  F or  the  salivary  glands  being  inactive 
during  foetal  existence,  have  only  an  intermittent  action  during  per- 
fect life;  and,  therefore,  probably  stand  in  need  of  a supplementary 
organ  during  their  periods  of  inactivity. 


86 


ORGANS  OF  DIGESTION. 


SECT.  III. — OF  THE  PANCREAS.* 

The  Pancreas  ( Pancreas ) secretes  saliva,  and  is  the  largest  of  the 
salivary  glands.  It  is  fixed  in  the  lower  back  part  of  the  epigastric 
region ; and  extends  horizontally  across  the  spine,  being  separated 
from  it  by  the  lesser  muscle  of  the  diaphragm.  It  is  connected  to 
the  spleen  on  the  left ; at  its  right  extremity  is  surrounded  by  the 
curvature  of  the  duodenum;  is  bounded  in  front  by  the  stomach, 
which  conceals  it;  and  is  placed  between  the  two  laminse  of  the 
mesocolon. 

The  pancreas  is  about  six  or  seven  inches  long,  two  wide,  and 
flattened  before  and  behind.  Its  figure  would  be  represented  by  a 
parallellogram,  were  it  not  that  its  right  extremity  is  enlarged  con- 
siderably into  a head  or  tuber,  to  which  Winslow  gave  the  name  of 
the  Lesser  Pancreas.  The  anterior  face  of  this  organ  is  turned  ob- 
liquely upwards,  and  is  covered  by  the  superior  lamina  of  the  meso" 
colon.  The  posterior  face  looks  obliquely  downwards,  and  is  in 
contact  with  the  aorta,  the  vena  cava  ascendens,  the  superior  mesen- 
teric vessels,  and  several  nerves  : along  the  superior  margin  of  this 
face  exists  a long  superficial  fossa,  occupied  by  the  splenic  artery 
and  vein. 

With  the  exception  of  the  loose  covering  given  by  the  meso- 
colon, the  pancreas  has  no  peritoneal  coat;  neither  has  it  an  ap- 
propriate tunic,  unless  we  consider  as  such  the  lamina  of  con- 
densed cellular  membrane  which  envelops  it,  and  sends  in  processes, 
between  its  lobules,  as  in  the  case  of  the  salivary  glands  in  the 
neck. 

Of  the  Minute  Structure  of  the  Pancreas. — This  body,  like  the 
other  glands,  w'hich  discharge  saliva,  is  of  a light  gray  or  pink 
colour.  It  consists  in  lobules  of  various  forms  and  sizes,  united 
by  an  intermediate  cellular  tissue,  and  having  their  interstices  occu- 
pied by  numerous  blood  vessels.  These  lobules,  by  a slight  mace- 
ration, may  be  separated  and  resolved  into  small  granular  masses, 
constituting  integral  portions  of  the  gland. 

The  arteries  of  the  pancreas  come  principally  from  the  splenic, 
as  it  cruises  along  the  superior  margin.  The  veins  empty  into  the 


* Anat.  Atlas,  Fig.  354. 


THE  SPLEEN. 


87 


splenic,  and  thus,  finally,  into  the  vena  portarum.  It  is  furnished 
with  nerves  from  the  solar  plexus,  and  has  lymphatics. 

The  excretory  duct  of  this  gland  ( Ductus  Wirsungii ) arises,  by 
very  fine  roots  or  tubes,  from  each  of  the  small  granular  masses. 
These  roots  have  vesicular  commencements  like  those  of  the  sali- 
vary glands.  The  tubes  coalesce  into  larger  ones,  which  run  trans- 
versely from  the  periphery  towards  the  centre  of  the  gland,  inclining 
slightly,  at  the  same  time,  towards  the  right.  These  secondary  tubes 
finally  discharge  successively  into  a single  one,  which  runs  the  whole 
length  of  the  gland  nearly  in  its  middle.  The  single  tube,  by  these 
additions,  enlarges  continually  from  left  to  right,  being  small  where 
it  begins  at  the  splenic  extremity  of  the  pancreas,  and  about  the  size 
of  a crow-quill  at  the  duodenal.  At  the  latter  place,  it  is  joined  by 
the  duct  of  the  lesser  pancreas,  which  is  derived  after  the  same  rule 
as  itself.  The  pancreatic  duct,  almost  immediately  afterwards,  emp- 
ties into  the  ductus  communis  choledochus ; or  runs  at  the  side  of 
the  latter,  and  makes  a distinct  opening  near  it  into  the  duodenum, 
at  the  posterior  part  of  the  second  curvature. 

The  diameter  of  the  cell-like  extremities  of  the  duct  of  the  Pan- 
creas is  from  six  to  twelve  times  greater  than  that  of  the  capillary 
blood  vessels. 


BOOK  V. 


OF  THE  URINARY  ORGANS. 

The  Urinary  Organs,  ( Organa  Oropoietica)  being  destined  to 
secrete  and  convey  the  urine  out  of  the  body,  consist  in  the  Renal 
Capsules,  the  Kidneys,  the  Ureters,  the  Bladder  and  the  Urethra. 


Of  the  Renal  Capsules. 

The  Renal  Capsules  ( Capsules  Renales , Renes  Succenturiati ,)  are 
two  small  bodies,  one  on  either  side,  placed  upon  the  upper  end  of 
the  kidney.  They  are  of  a yellowish  brown  colour  tinged  with  red, 
have  no  excretory  ducts,  and  are  more  distinctly  developed  and 
softer  in  the  perfect  foetus  than  in  the  adult ; whence  they  are  ranked 
among  those  organs,  as  the  thymus  gland,  and  others  ; which,  having 
some  peculiar  value  in  foetal  existence,  are  perhaps  unnecessary  to 
that  of  the  adult. * They  are  of  a triangular  pyramidal  shape,  flat- 
tened before  and  behind,  and  rest  by  a concave  base  upon  the  kid- 
neys ; they  are  about  fifteen  lines  high  and  as  many  wide. 

They  are  surrounded  by  a proper  coat  of  lamellated  dense  cel- 
lular tissue,  which,  by  detaching  inwards  its  prolongations,  keeps 
the  parts  of  these  bodies  together,  and  marks  out  their  divisions. 
In  the  centre  of  the  renal  capsule,  a cavity  may,  from  time  to  time, 
be  found ; but,  according  to  my  own  observations,  nothing  in  our 
structure  is  less  certain  than  its  existence ; and,  in  the  opinion  of 
Meckel,  when  found,  it  is  the  result  of  cadaverous  decomposition. 
In  the  foetus  it  contains  a reddish  viscid  fluid,  which  seems  to  con- 
sist in  a large  share  of  albumen,  as  it  coagulates  with  alcohol;  in 

* This  opinion  has  been  confirmed  in  a dissection  of  a fetus,  where  I found 
the  capsulae  renales,  though  the  kidneys  were  absent. 

Vol.  II.— 9 


90 


USINARY  ORGANS. 


\ 


children,  this  fluid  becomes  yellow:  in  adults  it  is  dark  brown  ; and 
in  old  people  it  is  either  entirely  deficient,  or  in  a remarkably  small 
quantity. 

Of  the  Minute  Structure  of  the  Capsules  Renales. — The  arteries 
of  these  bodies  come  from  the  emulgents,  from  the  phrenics,  and 
from  the  aorta.  The  veins  of  the  right  one  terminate  in  the  cava 
ascendens,  and  of  the  left  in  the  left  emulgent.  Each  one  is  divisible 
into  lobes,  and  by  a slight  maceration  may  be  reduced  into  lobules 
and  small  granulations.  The  granulations  seem  to  have  an  intimate 
connexion  with  the  veins,  as  they  are  easily  penetrated  by  fluid  in- 
jections from  the  latter.  The  external  part  is  rather  more  consistent 
and  yellow  than  the  internal ; hence,  a division  has  been  adopted 
into  cortical  and  medullary  portions. 

In  the  cortical  portion,  the  minute  arteries  and  veins  are  about 
the  size  of  the  capillaries  of  other  parts,  and  are  of  nearly  uniform 
magnitude.  They  are  arranged  in  a radiated  manner,  so  as  to  run 
in  lines  from  the  surface  towards  the  centre.  The  arteries  anasto- 
mose with  the  adjoining  branches,  so  as  to  form  very  long  meshes: 
the  veins  do  the  same.  On  the  periphery  of  the  organ  there  is  an 
ordinary  capillary  net-work  of  vessels.  A spongy  venous  tissue 
composes  the  greater  part  of  the  medullary  or  more  interior  portion  ; 
this  spongy  tissue  receives  the  radiated  venous  branches  of  the  ex- 
terior, and  discharges  its  own  blood  into  a large  vein  (Vena  supra- 
renalis)  in  the  interior  of  the  organ.  Muller,*  in  addition  to  the 
above,  says  that  the  only  cavity  in  this  organ  is  the  vein  just  alluded 
to,  and  that  by  forcing  air  into  the  vein  the  whole  medullary  tissue 
may  be  distended. 

Examination  with  the  microscope,  by  Mr.  Gulliver, f exhibited  the 
proper  structure  or  pulp  as  formed  of  spherules,  from  the  m-ho  to 
the  Wtni  of  an  inch. 

Alleged  excretory  ducts  for  these  bodies  have  been  found  going 
to  the  testicle,  to  the  pelvis  of  the  kidney,  and  to  the  thoracic  duct, 
but  no  credit  is  now  attached  to  such  assertions. 

* Physiol.,  p.  621. 

j Gerber’s  General  Anatomy,  Appendix,  p.  103.  London,  1842. 


THE  KIDNEYS. 


91 


Of  the  Kidneys.* 

The  Kidneys  ( Renes ) are  two  glandular  bodies  for  the  secretion 
of  urine,  fixed  one  on  either  side  of  the  spine.  They  are  in  the 
back  part  of  the  lumbar  regions,  have  their  internal  edges  inclining 
very  slightly  forwards,  and  extend  from  the  upper  margin  of  the 
eleventh  dorsal  to  the  lower  margin  of  the  second  lumbar  vertebra : 
the  right,  however,  is  ten  or  twelve  lines  lower  than  the  left,  owing 
to  the  thick  posterior  margin  of  the  right  lobe  of  the  liver,  which 
presses  it  downwards.  The  kidneys  are  covered  in  front  by  the 
peritoneum  and  the  lumbar  portions  of  the  large  intestine,  but  in 
such  a manner  as  to  be  separated  from  them,  in  corpulent  subjects, 
by  a surrounding  layer  of  fat ; behind,  they  repose  upon  the  lower 
part  of  the  great  muscle  of  the  diaphragm,  upon  the  quadrati  lum- 
borum,  and  upon  the  upper  end  of  the  psose  magni  muscles. 

The  kidney  is  a hard  solid  body,  of  a brown  colour ; in  shape  it 
is  a compressed  ovoid,  excavated  on  the  margin  which  it  presents 
to  the  spine,  and  bears  a very  strong  resemblance  to  the  common 
kidney  bean.  Its  flat  surfaces  present  forwards  and  backwards,  and 
the  broad  end  of  the  ovoid  is  above.  Its  periphery  is  smooth,  so 
that  one  does  not  infer  from  an  external  examination,  the  lobules  or 
internal  divisions.  The  excavation  of  the  kidney,  next  to  the  spine 
and  called  its  fissure,  ( hilum  renale ) occupies  about  one-third  of  its 
long  diameter,  is  bevelled  in  front,  and  leads  to  the  very  interior  of 
the  gland;  conducting  its  blood  vessels  and  excretory  duct,  which 
have  to  pass  through  a quantity  of  cellular  and  adipose  matter.  The 
kidneys  are  generally  of  equal  size,  being  about  four  inches  long, 
and  two  wide ; and  each  one  weighs  three  or  four  ounces.  They 
have  no  ligaments  for  keeping  them  in  position,  but  depend  for  the 
latter  upon  the  adjacent  cellular  adhesions  and  blood  vessels. 

The  kidney  being  destitute  of  a peritoneal  coat,  has  a well  marked 
capsule  which  envelopes  it  entirely  and  penetrates  into  its  fissure  for 
some  depth,  where  it  is  perforated  with  foramina  for  transmitting  the 
blood  vessels  and  the  ureter.  This  capsule  is  white,  semi-trans- 
parent, fibrous,  strong,  and  elastic : it  adheres  to  the  surface  of  the 
kidney  by  delicate  cellular  and  vascular  filaments,  which  are  so 
weak  that  they  permit  it  to  be  stripped  off  without  difficulty,  and 


* Anat.  Atlas,  Figs.  356  to  368,  inclusive. 


92 


URINARY  ORGANS. 


when  so  removed,  some  indications  of  a lobulated  condition  of  the 
organ  are  seen. 

Of  the  Minute  Structure  of  the  Kidney. — The  lobulated  state  of 
the  kidney  is  well  marked  in  the  foetus ; and  some  of  the  lower  orders 
of  animals,  as  the  bullock,  exhibit  it  very  clearly  through  life.  In 
the  human  adult  subject,  by  tearing  the  kidney  up  according  to  the 
superficial  lines  marking  a tendency  to  the  lobulated  condition,  it 
will  be  found  that  there  are  really  about  fifteen  divisions  of  it,  more 
or  less,  each  of  which  constitutes  a small  kidney  (Renculus.)  When 
the  kidney  is  cut  open  longitudinally,  it  obviously  consists  of  twro 
kinds  of  substance,  differing  in  their  situations,  colour,  consistence, 
and  texture.  The  one  making  the  periphery  of  the  gland  is  called 
from  its  position  Cortical,  ( Substantia  Corticalis,  Gla?idulosa,)  while 
the  other,  being  more  internal,  is  designated  as  the  Medullary  or 
Tubular,  (Substantia  Medullaris  ; Tubulosa  ; Fibrosa.) 

The  Cortical  or  Secretory  Substance  forms  the  whole  circumfer- 
ence of  the  kidney,  and,  on  an  average,  is  about  two  lines  in  thick- 
ness ; but  it  is  thicker  at  some  points,  as,  from  its  internal  face,  pro- 
cesses converge  towards  the  centre  of  the  gland,  which  separate  the 
tubular  part  into  as  many  distinct  portions  of  a conoidal  shape.  It 
is  composed  largely  of  arteries  and  veins  ramifying,  among  small 
granular  corpuscles  (Corpora  Malpighiana,  or  Glomeruli.)  It  tears 
with  facility,  thereby  presenting  this  granular  appearance,  and  is  of 
a dark  or  reddish  brown  colour,  varying  considerably,  however,  ac- 
cording to  the  cause  of  death. 

The  Granular  corpuscles  which  form  the  mass  of  the  cortical  or 
secretory  substance,  are,  individually,  merely  visible  to  the  naked 
eye;  but  are  very  distinct  when  viewed  with  a microscope.  They 
present  themselves  as  innumerable  small  round  points  more  red 
than  the  other  portions  of  the  surface  inspected.  Their  diameter 
approaches  the  tenth  of  a line,  some  being  less.  They  are  attached 
to  very  fine  arterial  twigs,  like  a berry  to  its  stem,  and  are  so  dis- 
engaged in  their  position  in  the  cortical  part  of  the  kidney  that  they 
may  be  lifted  out  of  their  beds  with  the  point  of  a needle,  especially 
in  the  horse. 

The  celebrated  Ruysch,  who  was  distinguished  for  the  success  ot 
his  injections,  and  for  the  acuteness  of  his  vision,  declared  that  they 
consisted  wholly  in  clusters  of  very  fine  extremities  of  arteries 


THE  KIDNEYS. 


93 


and  veins  having  a penicillous  arrangement;  while  Malpighi  and 
Schumlansky  viewed  them  as  purses  or  small  sacs  of  a glandular  cha- 
racter, specifically  suited  to  secrete  urine,  and  upon  whose  parietes 
the  blood  vessels  ramified.  From  these  granuli  or  acini  the  incipient 
extremities  of  the  tubuli  uriniferi,  they  asserted,  take  their  rise. 

The  Tubular  or  Conoidal  Substance,  consists  in  from  twelve  to 
eighteen  conoidal  fasciculi,  say  on  an  average  fifteen  [Pyr amides 
Malpighiance ) presenting  their  rounded  bases  towards  the  cortical 
matter,  and  enclosed  in  it,  while  their  apices  converge  to  the  central 
cavity  of  the  kidney,  the  surface  of  which  they  form.  The  bodies 
of  these  pyramids,  as  just  mentioned,  are  separated  by  processes  of 
the  cortical  matter;  but  their  apices  are  free,  and  project  from  the 
internal  surface  of  the  kidney  so  as  to  resemble  as  many  small  nip- 
ples, whence  they  are  called  Papillae  or  Mammellae  Renales.  Fre- 
quently two  of  the  pyramids  coalesce  so  as  to  form  but  one  papilla 
together ; in  such  case  the  latter  generally  preserves  a duplicate  ap- 
pearance. The  papillae  are  arranged  into  three  vertical  rows,  one 
before,  one  in  the  middle,  and  another  behind  ; those  of  the  foremost 
row  are  turned  backwards  ; those  of  the  middle  look  inwards  ; and 
those  behind  look  forwards.  Not  unfrequently,  there  is  a small  de- 
pression (foveola)  on  the  very  summit  of  the  papilla.  The  tubular 
part  is  of  a lighter  colour  and  harder  than  the  cortical,  but  the  dif- 
ference in  these  respeets  is  not  always  manifest  and  sometimes  is 
reversed. 

The  conoidal  fasciculi  may  each  be  considered,  along  with  its 
appertaining  cortex,  as  a sort  of  distinct  gland  ( Renculus ,)  or  at  least 
as  a lobe ; for  upon  them  depends  the  lobulated  appearance  as  stated 
of  the  kidney  of  a foetus,  and  of  animals.  Each  cone,  when  analy-. 
zed,  is  found  to  consist  in  a collection  of  tubes  (Ductus  Uriniferi 
Bellini ) converging  from  the  ciicumference  of  the  kidney  to  the  apex 
of  the  papilla.  These  tubes  are  more  numerous  near  the  base  of  the 
cone,  in  consequence  of  their  successive  junction  subsequently  in 
approaching  the  apex  :*  their  terminating  orifices,  on  the  latter,  ap-. 
pear  like  small  pores  from  which  the  urine  can  be  squeezed  in  little 
drops. 

In  the  early  part  of  the  course  of  the  ductus  uriniferi,  while  they 

* Schumlansky,  Diss.  de  Struct.  Renum,  Strasburg,  1782. 

9* 


94 


URINARY  ORGANS. 


are  still  in  the  cortical  matter,  they  are  wound  about  in  a very  ser- 
pentine and  tortuous  manner,  and  are  distinguished  by  the  name  of 
Cortical  Canals,  ( Ductus  Ferrenii .* * * §)  They  there  commonly  go  alone, 
winding  their  way  in  the  cortical  substance  until  they  reach  its  most 
interior  face ; they  then  become  straight,  form  the  tubular  substance, 
and  have  the  name  of  the  conduits  or  uriniferous  ducts  of  Bellini. f 

Some  of  the  calculations  on  this  subject  are  not  a little  curious. 
It  was  ascertained  by  Ferrein  that  in  each  of  the  conoidal  fasciculi 
(Pyr  amides  Malpigl nance)  there  were,  at  least  seven  hundred  subor- 
dinate cones  or  pyramids,  ( Pyr amides  Ferrenii ) and  as  the  number 
of  conoidal  fasciculi  is  generally  about  fifteen,  these  pyramids  would 
amount  to  ten  thousand  five  hundred.  Again,  each  of  the  subordi- 
nate pyramids  is  composed  of  many  hundred  uriniferous  tubes,  and, 
by  the  observations  of  Eysenhardt,j;  each  of  these  tubes  consists  of 
twenty  smaller  ones. 

The  cortical  canals  or  ducts  of  Ferrein,  it  is  believed  by  many, 
terminate  at  their  peripheral  extremity,  by  forming  loops  upon  them- 
selves, and  anastomoses  with  contiguous  similar  canals.  § It  is  also 
held  by  some,  as  Wagner,  that  in  addition  to  this  mode  of  termina- 
tion others  of  those  canals  end  in  caeca  or  blind  extremities,  which 
are  either  single  or  bifid.  Should  the  observations  in  this  respect 
turn  out  correct,  the  arrangement  has  been  at  least  found  more  de- 
cided and  frequent  in  the  lower  animals  than  in  man. 

Iduschke|]  and  John  MullerU  have  denied  the  connexion  of  the 
Granular  corpuscles  with  the  Ducts  of  Ferrein.  The  former  says  that 
if  the  ureter  be  injected  by  the  pneumatic  machine,  the  injection  will 
be  found  never  to  reach  the  Malpighian  corpuscles,  though  an  injec- 
tion of  the  arteries  at  the  same  time  will,  and  the  two  injections  will 
remain  apart.  He  hence  infers  that  these  bodies  are  merely  the 
twisted  tufted  ends  of  the  blood  vessels,  being  an  arrangement 
preparatory  to  the  real  secretion  of  urine  from  a subsequent  capillary 
network,  made  of  arteries  and  of  veins.  This  network  surrounds 
the  cortical  canals,  and  is  displayed  upon  them,  without,  however, 
anastomosing  with  them.  In  opposition  to  this  view,  besides  the 

* A.  Ferrein;  sur  la  Structure  des  reins  et  du  foie.  Mem.  de  l’Ac.  des 
Sc.  Paris,  1749. 

j-  L.  Bellini,  de  Structura  Renum  Florence,  1662. 

f:  De  Struct.  Renum  Obs.  Micros.  Berlin,  1818. 

§ Muller,  Krause,  Owen,  Weber,  See  Muller’s  Physiol.  2nd  ed.  p.  496. 

||  Traite  de  Splanch.  p.  298. 

De  Gland  Struct.  Leips.  1830. 


THE  KIDNEYS. 


95 


testimony  of  preceding  anatomists,  we  have  a very  good  paper,  by 
W.  Bowman,  of  King’s  College,  London,* * * §  showing  by  injections 
this  connexion  of  the  corpuscles  and  the  ducts  of  Ferrein;  and  that 
the  arteries  and  veins  make  there  a tufted  junction  with  one  another. 
He  asserts  that  each  one  of  these  corpuscles  is  actually  included 
in  the  extremity  of  an  uriniferous  tube,  which  enlarges  to  receive 
it,  that  the  arterial  filament  that  supplies  it  after  forming  its  tuft 
emerges  as  an  efferent  trunk,  and  is  then  merged  in  the  capil- 
lary plexus  investing  the  uriniferous  tubes.  This  view  has  been 
measurably  confirmed  by  Gorlach.f 

It  appears  that  in  the  Boa  Constrictor,  there  is  a vena  portarum  to 
the  kidney — some  approach  to  which  Bowman  considers  to  exist 
in  the  human  subject,  under  an  arrangement  stated  by  him. 

The  Kidney  receives  from  the  aorta  one 
or  more  branches,  called  the  renal  or  emul- 
gent  arteries,  which  divide  as  they  approach 
the  fissure  ; and  having  got  into  the  substance 
of  the  gland  are  distributed  by  innumerable 
twigs  to  all  parts  of  it.  The  veins  equal  in 
number  the  arteries,  and  are  somewhat  larger. 

When  both,  or  even  one,  of  these  systems  of 
blood  vessels  is  injected  with  wax  and  cor- 
roded, its  branches  are  so  abundant  as  to  re- 
tain the  form  of  the  gland.  In  engaging  in 
the  fissure  of  the  kidney,  the  arterial  ramifi- 
cations are  in  front,  the  veins  in  the  middle, 
and  the  commencement  of  the  ureter  be- 
hind^ The  artery  on  the  right  side  is 
longer  than  that  on  the  left.  The  reverse  is 
the  case  with  the  emulgent  veins,  as  they 
empty  into  the  vena  cava  ascendens.  This 
arrangement  is  owing  to  the  relative  position 
of  the  aorta  and  the  vena  cava  ascendens,  as 
the  first  is  on  the  left  side  of  the  spine,  and 
the  last  on  the  right  side. 

The  arteries  of  the  kidney,  in  ramifying 

* Transactions  Royal  Society,  London,  part  1st,  1842. 

f Am.  Journ.  Med.  Sciences,  p.  442.  April,  1846. 

X According-  to  Bowman  magnified  about  thirty  diameters. 

§ This  rule  is  subject  to  frequent  variations. 


Fig.  29. f 


Arrangement  of  the  Re- 
nal vessels;  in  the  Kidney 
of  the  Horse: — a,  branch 
of  Renal  artery  ; af,  affe- 
rent vessel ; m,  m,  Mal- 
pighian corpuscles;  ef,  ef. , 
efferent  vessels; p,  vascu- 
lar plexus  surrounding 
the  uriniferous  tubes;  st , 
tube  of  Bellini,  ct,  tube 
of  Ferrein. 


96 


URINARY  ORGANS. 


minutely  through  its  structure,  adopt  the  following  arrangement. 
They  first  of  all  pass  through  the  processes  sent  inwards  from  the 
cortical  matter  between  the  Pyramids  of  Malpighi,  or  large  cones 
and,  having  got  fairly  into  the  cortical  matter,  they  divide  into  very 
fine  twigs,  which  form  arcades  around  the  bases  of  the  pyramids  of 
Ferrein,  and  pass  between  them.*  These  arcades  have  anastomoses 
with  each  other,  and  their  larger  branches  go  almost  exclusively  to 
the  cortical  substance,  but  few  of  them  being  found  on  the  tubular. 
The  branches  radiate  from  the  convexities  of  the  arches,  so  as  to 
surround  the  base  of  each  cone,  and  to  penetrate  to  the  surface  of 
the  kidney.  Some  of  these  branches  terminate  in  corresponding 
veins,  and  others  on  the  granular  corpuscles  or  acini. 

The  connexion  between  the  corpuscles  and  the  arteries,  has  been 
compared  to  that  between  grapes  and  the  stems  on  which  they  grow,  so 
as  to  form  a bunch.  The  veins  penetrate  the  substance  of  the  kidney, 
and  have  a similar  distribution ; but  they  are  much  larger  than  the 
arteries,  and  have  free,  large  and  numerous  anastomoses.  A con- 
nexion of  the  corpuscles  with  the  veins  is  not  quite  so  evident,  and, 
even  if  it  does  exist,  remains  yet  to  be  adequately  proved ; at  least, 
in  the  opinion  of  many  anatomists.  The  fact,  however,  is  well  esta- 
blished, that  fine  injections  will  readily  pass  from  the  veins  into  the 
tubuli  uriniferi;  and  that  air  blown  into  the  ureter  will  pass  readily 
into  the  veins.  In  my  own  injections  these  have  been  done  repeatedly, 
and  the  corpuscles  of  Malpighi  are  seen  very  distinctly  to  be  formed 
of  convoluted  arteries;  I have  not  seen  the  veins  convoluted  under 
the  same  arrangement,  neither  have  I succeeded  in  tracing  the  corti- 
cal canals  to  these  corpuscles  or  acini. 

From  the  concave  side  of  the  arterial  arcades  very  fine  capillary 
branches  converge  in  company  with  the  ducts  of  Bellini  in  a line 
with  them,  and  penetrate  to-  the  free  surface  of  the  papillae  renales. 
Upon  this  surface  is  made  a highly  attenuated  capillary  intertexture, 
the  meshes  of  which  surround  the  orifices  of  the  tubuli  uriniferi.  The 
converging  arteries  anastomose  across  the  tubuli,  making  elongated 
meshes.  A similar  arrangement  of  the  veins  takes  place  from  their 
cortical  branches  and  arcades,  it  being  in  company  with  the  arterial 
arrangement.  The  facility  of  injecting  these  minute  tubular  arteries 
and  veins  has  frequently  given  rise  to  the  mistake  of  considering  them 
as  the  tubuli  uriniferi  themselves ; an  error  which  has  been  pointedly 
marked  out  by  Miiller.f 


* Schumlansky. 


f Physiol,  p.  225. 


THE  KIDNEYS. 


97 


The  nerves  of  the  kidneys  come  from  the  solar  plexus  of  the  sym- 
pathetic ; and  adhering  to  the  arteries  cannot  be  traced  very  far 
through  the  glandular  structure.  The  quantity  of  lymphatics  is  con- 
siderable. 

The  kidneys  are  subject  to  a false  position ; in  one  instance,  I 
found  in  a young  female  subject,  one  of  the  kidneys  in  the  pelvis  in 
front  of  the  rectum.  A similar  case  has  been  seen  by  Professor  Hen- 
singer,*  and  since  then,  others  have  been  recorded.  I have  met  with 
several  instances  of  a coalition  of  the  two  kidneys,  across  the  spine, 
so  as  to  present  the  appearance  of  a bilobed  organ. 


Of  the  Excretory  Dud  of  the  Kidney , or  the  Ureter,  f 

The  Ureter  is  a canal  which  conveys  the  urine  from  the  kidney  to 
the  bladder.  It  commences  in  the  centre  of  the  kidney  by  an  en- 
largement called  pelvis , which  branches  off  into  three  or  four  por- 
tions, ( calices} ) one  above,  one  below,  and  one  or  two  intermediate. 
Each  of  these  calices,  is  divided  at  its  free  extremity,  into  three  or 
four  short  funnel-shaped  terminations,  ( Infundibula .)  Each  of  these 
terminations  embraces  by  its  expanded  orifice,  the  base  of  a papilla 
renalis,  so  as  to  permit  the  latter  to  project  into  it,  and  thereby  to  distil 
its  urine  there.  Very  frequently  the  number  of  papillae  exceeds  that  of 
the  infundibula,  in  which  case  two  of  the  former  project  into  one  of 
the  latter. 

The  pelvis  of  the  kidney  having  emerged  at  the  fissure  behind  the 
vessels,  from  being  expanded  and  conoidal  in  shape  is  reduced  to  a 
cylindrical  canal,  which,  properly  speaking,  is  the  ureter : the  latter 
is  about  the  size  of  a goose-quill,  and  descends  through  the  lumbar 
region,  between  the  peritoneum,  and  the  psoas  magnus  muscle.  It 
dips  into  the  pelvis  by  crossing  in  front  of  the  primitive  iliac  vessels 
and  the  internal  iliac,  crosses  the  vas  deferens  at  the  back  of  the 
bladder,  and  penetrating  obliquely  the  coats  of  the  latter,  terminates 
in  an  orifice  ten  or  twelve  lines  behind  that  of  the  neck  of  the 
bladder. 

I he  excretory  duct  of  the  kidney  is  formed  by  two  coats.  The 
external  is  a dense,  fibrous,  and  cellular  tissue,  but  is  destitute  of 
any  thing  like  muscle.  The  internal  is  a thin  mucous  lamina,  which 

* Amer.  Med.  Jour.,  Yol.  iii.  p.  442. 
f Anat.  Atlas,  Fig.  359. 


9S 


URINARY  ORGANS. 


can  be  raised  up  without  much  difficulty,  and  is  continuous,  at  its 
lower  end,  with  the  internal  coat  of  the  bladder  ; at  the  upper  end, 
it  is  supposed  by  some  anatomists  to  be  reflected  over  the  papillm, 
and  even  to  pass  for  some  distance  into  the  tubuli  uriniferi.  This 
duct  has  considerable  powers  of  extension,  as  manifested  by  its 
transmitting  large  calculi  from  the  kidney,  and  also,  by  its  enormous 
enlargement  in  some  cases  of  obstructed  urethra  ;*  its  sensibility  is 
exquisite  when  irritated  by  a calculus  passing  down  it. 

The  walls  of  the  tubuli  uriniferi  are  the  surface  upon  which  the 
secretion  of  urine  most  probably  takes  place  exclusively.  The  mu- 
cous membrane  of  the  pelvis  of  the  kidney  being  continued  over  them 
so  as  to  form  the  surface;  these  canals,  delicate  as  they  are,  exhibit 
an  epithelium  formed  of  nucleated  cells.  These  cells,  discovered  by 
Henle,  are  close  together  without  being  angular ; according  to  the  phy- 
siological views  of  the  case  in  all  glands,  they  are  the  real  elaborators 
of  the  urine,  and  upon  becoming  distended  with  it,  they  burst,  and 
let  out  their  contents  into  the  tubuli  uriniferi;  being  then  decomposed 
a new  generation  of  cells  is  produced  from  the  nuclei  of  the  extinct 
ones.  They  have  to  pass  through  the  same  series  of  changes,  and, 
thus  it  proceeds  to  the  end  of  life. 

Corpora  Wolffiana .f 

The  Corpora  Wolffiana,  called  after  their  discoverer,  are  small 
bodies  found  only  in  the  earlier  stages  of  foetal  life,  one  on  each  side 
in  the  lumbar  region,  and  of  which  there  are  scarcely  any  traces  at 
the  end  of  the  fifth  month.  When  in  full  development,  they  are  so 
large  as  to  conceal  the  kidneys  and  the  renal  capsules,  but  as  these 
latter  organs  grow,  the  corpora  Wolffiana  diminish,  and  are  finally 
placed  lower  down.  They  are  supposed  to  be  vicarious  kidneys  for 
the  time,  and  they  consist  in  transverse  coscal  tubes,  which  are  nu- 
merous. They  have  each  an  excretory  duct,  which  leads  from  their 
lower  part  into  the  Sinus  Uro-genitalis. 

The  latter  is  also  peculiar  to  the  foetal  state,  and  is  a tube  which  for 
the  time  receives  from  each  side  the  ureter,  the  vas  deferens,  and  the 
duct  of  the  corpus  Wolffianum  ; and  is  prolonged  into  the  urachus. 
The  Sinus  Uro-genitalis  is  finally  divided  into  two  branches,  from 

* See  Wistar  Museum, 
f Anat.  Atlas,  Fig.  369. 


THE  BLADDER. 


99 


one  of  which  is  evolved  the  urinary  bladder,  and  from  the  other  the 
vesiculse  seminales.* * * § 


Of  the  Bladder. \ 

The  Bladder  ( Vesica  Urinaria ,)  is  the  reservoir  for  the  urine,  and 
is  placed  in  the  pelvis,  just  behind  the  symphysis  of  the  pubes. 
When  pressed  upon,  as  it  commonly  is,  by  the  adjacent  viscera,  it 
is  flattened  somewhat  before  and  behind ; but  removed  from  the 
body  and  inflated,  it  is  an  elongated  sphere  or  an  oval:  the  greatest 
diameter  of  which  is  vertical,  in  regard  to  the  linea  ileo-pectinea. 
The  superior  end  of  the  bladder  is  called  the  upper  fundus,  and  the 
lower  end  the  inferior  fundus ; the  latter  is  rather  more  obtuse  than 
the  other;  and  between  the  two  is  the  body.  The  neck  of  the  blad- 
der is  its  place  of  junction  with  the  urethra.  The  form  of  the  bladder 
is  influenced  by  age  and  by  sex;  in  very  young  infants  it  is  cylin- 
droid,  and  owing  to  the  smallness  of  the  pelvis,  rises  up  almost  wholly 
into  the  abdomen.  In  the  adult  woman,  who  has  frequently  borne 
children,  it  is  nearly  spherical,  has  its  greatest  diameter  transverse,  J 
and  is  more  capacious  than  in  man. 

The  bladder  is  bounded  in  front  by  the  pubes,  above  by  the  small 
intestine,  behind  by  the  rectum,  and  below  by  the  prostate  gland  and 
the  vesiculse  seminales.  From  its  superior  end  there  proceeds  to  the 
umbilicus  a long  conical  ligament,  the  urachus,  which  is  placed  be- 
tween the  linea  alba  and  the  peritoneum,  and  produces  a slight  ele- 
vation or  doubling  of  the  latter.  In  mankind,  the  urachus  is  solid ; 
but  some  very  rare  cases  are  reported,  in  which  it  has  been  hollow, 
so  as  to  permit  the  urine  to  flow  through  it  from  the  bladder.  This 
anomalous  conformation  has  generally  been  attended  with  a con- 
genital obstruction  of  the  urethra.  § When  the  anterior  parietes  of 
the  abdomen  are  put  upon  the  stretch,  a semi-lunar  fold  of  the  peri- 
toneum, as  formerly  mentioned,  is  seen  to  proceed,  on  either  side  of 
the  urachus,  from  the  lateral  surface  of  the  bladder  almost  to  the  um- 
bilicus. These  folds  contain,  in  their  free  edge,  the  fibrous  remains 
of  the  umbilical  arteries  of  the  foetus,  called  subsequently  to  uterine 
life,  the  Round  Ligaments  of  the  bladder,  though  they  have  little  or 

* Muller’s  Phys.,  p.  1639. 

f Anat.  Atlas,  Figs.  370  to  375,  inclusive. 

X H.  Cloquet,  Anat.  Descrip. 

§ Sabatier,  Anat.,  vol.  iii.  p.  19. 


100 


URINARY  ORGANS. 


no  influence  on  its  position.  The  bladder  is  also  fixed  in  its  situation 
by  the  pelvic  aponeurosis,  a membrane  elsewhere  described  with  the 
organs  of  generation. 

The  bladder  consists  of  four  coats : the  Peritoneal,  the  Muscular, 
the  Cellular,  and  the  Mucous. 

The  Peritoneal  Coat  is  very  imperfect,  and  is  derived  from  the 
part  of  the  peritoneum  which  descends  from  the  anterior  parietes  of 
the  abdomen  into  the  pelvis.  It  covers  the  upper  and  the  posterior 
face  of  the  bladder,  and  then  passes  to  the  rectum,  by  sinking  down 
between  these  two  organs,  so  as  to  form  the  small  pouch  beneath  the 
lower  fundus  of  the  bladder  ; the  apex  of  this  pouch  reaches  within 
an  inch  of  the  base  of  the  prostate.  The  upper  margin  of  this  pouch 
next  to  the  bladder,  forms  a strong  horizontal  doubling,  stretching 
across  the  pelvis,  when  the  rectum  is  empty,  and  is  on  a level  with 
the  posterior  end  of  the  vesiculse  seminales.  Being  connected  to  the 
subjacent  muscular  coat  by  a thin  lamina  of  loose  cellular  membrane, 
the  peritoneum  may  be  dissected  off  without  difficulty.  In  consi- 
derable distentions  of  the  bladder,  it  is  reflected  from  the  upper  end 
of  the  latter  to  the  abdominal  muscles  in  a line  much  above  the 
pubes ; whereby  a good  opportunity  is  afforded  of  reaching,  with  an 
instrument,  the  cavity  of  the  bladder  without  injuring  the  perito- 
neum. 

The  Muscular  Coat  is  of  a thickness  intermediate  to  that  of  the 
stomach  and  of  the  oesophagus,  and  its  fibres  are  pale.  They  pass 
in  very  varied  directions,*  and  are  collected  into  flattened  fasciculi, 
leaving  interstices  between  them,  through  which  the  internal  coat  is 
occasionally  caused  to  protrude,  in  strictures  and  other  obstructions 
of  the  urethra.  Many  of  these  fasciculi,  arise  about  the  neck  of  the 
bladder,  and  ascending  upwards,  before,  behind,  and  laterally,  ter- 
minate at  the  superior  fundus  in  the  base  of  the  urachus.  Within 
these,  which  may  be  considered  as  the  longitudinal  fibres  of  the 
bladder,  there  are  others  forming  a thinner  lamina,  whose  course 
is  transverse  or  oblique : they  serve  to  connect  the  preceding.  As 
the  muscular  fibres  are  collected  at  the  neck  of  the  bladder,  and  at 
the  urachus,  there  is,  of  course,  an  increased  thickness  at  these 
points. 

The  Cellular  Coat  ( Tunica  propria)  like  that  of  the  alimentary 


* Santorini,  Septemd.  Tabul. 


THE  BLADDER. 


101 


canal  consists  in  a close,  dense,  lamellated,  and  filamentous  cellular 
tissue,  very  extensible  and  difficult  to  tear.  It  is  impervious  to 
water,  adheres  closely  to  the  muscular  coat  without,  and  to  the 
mucous  within,  so  as  to  form  a strong  bond  of  union  between  them. 
It  is  pervaded  by  many  vessels  and  nerves,  which  it  conveys  to  the 
mucous  coat. 

The  Mucous  Coat  is  also  called  the  villous,  but  is  much  more 
smooth  than  the  corresponding  one  of  the  stomach.  It  is  white, 
with  a slight  tinge  of  red,  and  abounds  with  mucous  follicles,  which 
though  small  and  scarcely  discernible  in  a natural  state,  are  rendered 
very  obvious  by  disease.  It  stretches  with  much  facility,  but  like 
other  mucous  membranes,  does  not  restore  itself  fully,  and  is  rather 
thrown  in  the  contracted  state  of  the  bladder,  into  wrinkles  or  folds, 
having  a diversified  course,  and  of  a fugitive  character,  as  they  dis- 
appear again  upon  the  next  distention.  It  is  very  vascular. 

The  internal  face  of  this  coat  presents,  at  its  inferior  part,  the  fol- 
lowing appearances. 

1.  The  Vesical  Triangle  ( Trig  onus  Lieutaudi,  Trigone  Vesicale ,) 
is  placed  immediately  behind  and  below  the  neck  of  the  bladder, 
occupying  the  space  between  it  and  the  orifices  of  the  ureters.  It  is 
an  equilateral  triangle  of  an  inch  in  length,  its  surface  is  smooth, 
is  not  affected  very  materially  in  extent  either  by  the  dilatation  or  the 
contraction  of  the  bladder,  and  is  elevated  so  as  to  be  sufficiently 
distinct  and  well  defined. 

2.  The  anterior  angle  of  the  triangle  looks  into  the  orifice  of  the 
urethra,  and  is  generally  so  elevated  that  it  has  obtained  the  name 
of  Uvula  Vesicas;  it  is,  however,  simply  a projection  of  the  mucous 
membrane  depending  upon  the  subjacent  third  lobe  of  the  prostate  ; 
which,  at  this  point,  is  not  unfrequently  much  enlarged  in  the  aged, 
and  then  presents  a great  difficulty  in  the  introduction  of  a catheter. 

3.  The  Orifices  of  the  ureters  form  the  posterior  angles  of  the 
triangle,  and  are  contracted  somewhat  below  the  size  of  the  canals 
themselves.  They  are  said  by  Sir  Charles  Bell,*  to  be  furnished, 
each  one,  with  a small  fasciculus  of  muscular  fibres,  which  runs 
backwards  from  the  orifice  of  the  urethra,  just  beneath  the  lateral 

* Med.  Chir.  Trans.  Vol.  iii. 

Vol  II.— 10 


102 


URINARY  ORGANS. 


margins  of  the  triangle,  and,  in  its  contraction,  will  stretch  the  ori- 
fice of  the  ureter  so  as  to  permit  an  easy  passage  of  the  urine  into 
the  bladder.  The  retrogradation  of  the  urine  is  prevented  by  the 
ureter  passing  obliquely,  for  six  or  eight  lines,  between  the  muscular 
and  the  mucous  coat;  there  is  something  also  in  the  obliquity  and 
elliptical  shape,  with  a defined  edge  of  the  orifice  itself  which  assists 
in  this  effect ; as  I have  ascertained  by  removing  the  muscular  coat 
entirely,  at  this  point,  and  dissecting  up  the  ureter,  notwithstanding 
which,  the  bladder,  when  inflated,  still  retained  its  contents.  Where 
the  ureter  penetrates  the  muscular  coat,  there  is  often  found  a layer 
of  longitudinal  muscular  fibres  ascending  and  enveloping  it  for  half 
an  inch,  or  an  inch. 

4.  The  Inferior  Fundus  of  the  bladder  ( Bas-fond  of  the  French) 
is  a depression  of  the  general  concavity  of  the  bladder,  of  about  six 
lines  in  depth,  placed  between  the  base  of  the  vesical  triangle  and 
the  posterior  side  of  the  bladder.  In  the  erect  position,  calculus, 
when  present,  lodges  there. 

5.  The  Internal  Orifice  of  the  neck  of  the  bladder  resembles 
strongly  that  of  a Florence  flask,  modified,  however,  by  the  projec- 
tion of  the  uvula  vesicae,  which  makes  it  somewhat  crescentic 
below.  The  neck  of  the  bladder  penetrates  the  prostate  gland  but, 
at  its  commencement,  is  surrounded  by  loose  cellular  tissue  contain- 
ing a very  large  and  abundant  plexus  of  veins.*  The  internal  layer 
of  muscular  fibres  is  here  transverse;  and  they  cross  and  intermix 
with  each  other  in  different  directions,  forming  a close  compact 
tissue,  which  has  the  effect  of  a particular  apparatus  for  retaining 
the  urine,  and  is  called  Musculus  Sphincter  Vesicae  Urinariee. 
Generally,  anatomists  have  not  considered  this  structure  as  distinct 
from  the  muscular  coat  at  large ; but  the  late  Sir  Charles  Bell,  Profes- 
sor in  the  University  of  Edinburgh,  whose  reputation  as  an  anatomist 
was  well  established,  gives  the  following  account  of  it. 

“ Begin  the  dissection  by  taking  off'  the  inner  membrane  of  the 
bladder  from  around  the  orifice  of  the  urethra.  A set  of  fibres  will 
be  discovered,  on  the  lower  half  of  the  orifice,  which,  being  care- 
fully dissected,  will  be  found  to  run  in  a semicircular  form  round 
the  urethra.  These  fibres  make  a band  of  about  half  an  inch  in 


* Mascagni,  Anat.  Univ.  Str.  Prim.  Tab.  Spec.  Fig.  V. 


THE  BLADDER. 


103 


breadth,  particularly  strong  on  the  lower  part  of  the  opening,  and, 
having  mounted  a little  above  the  orifice,  on  each  side,  they  dispose 
of  a portion  of  their  fibres  in  the  substance  of  the  bladder.  A 
smaller  and  somewhat  weaker  set  of  fibres  will  be  seen  to  complete 
their  course,  surrounding  the  orifice  on  the  upper  part;  to  these 
sphincter  fibres  a bridle  is  joined,  which  comes  from  the  union  of 
the  muscles  of  the  ureters.”* 

After  repeated  observations  on  this  point,  I have  come  to  the 
conclusion  that  Mr.  Bell  has  indicated  a real  structure ; but  my  own 
dissections  have  resulted  as  follows:  The  inferior  semicircumference 
of  the  neck  of  the  bladder  is  defined  by  a thick  fasciculus  of  mus- 
cular fibre,  half  an  inch  wide,  running  in  a transverse  direction,  and 
having  its  ends  attached  to  the  lateral  lobes  of  the  Prostate  Gland? 
being  above  the  third  lobe  of  the  latter.  This  fasciculus  is  perfectly 
distinct  from  the  ordinary  muscular  fibre  of  the  bladder,  and  re- 
sembles in  its  texture  the  musculo-fibrous  coat  of  the  arteries.  The 
superior  semicircumference  is  also  surrounded  by  a thin  layer  of 
muscular  fibres  of  the  ordinary  kind,  forming  a broad,  thin  band  of 
a crescentic  shape,  the  low’er  ends  of  which  are  insensibly  lost  in 
the  adjacent  muscular  coat  of  the  bladder  by  being  spread  out. 
And,  lastly,  beneath  the  mucous  membrane  of  the  vesical  triangle, 
there  is  a triangular  muscle  of  the  same  size  as  the  vesical  triangle. 
Having  elongated  angles,  the  anterior  angle  may  be  traced  to  the 
posterior  part  of  the  caput  gallinaginis,  and  the  posterior  angles  to 
the  orifices  of  the  ureters  and  the  adjacent  part  of  the  bladder.  The 
texture  of  this  muscle  is,  also,  like  that  of  the  musculo-fibrous  coat 
of  the  arteries.  When  a bladder  is  recent,  this  detail  of  structure 
is  made  out  with  difficulty : it  requires  to  be  previously  hardened 
in  spirits  of  wine.f  That  a power  exists  in  the  neck  of  the  bladder 
of  retaining  completely  the  urine,  has  been  satisfactorily  demonstrated 
to  me  in  a case  of  fistula  in  perineo,  wffiich  was  presented  to  the 
notice  of  the  late  Dr.  Physick  and  myself,  some  years  ago,|  as 
well  as  in  other  cases  occurring  since  then.  The  insertion  of  the 
muscle  of  the  vesical  triangle  into  the  caput  gallinaginis,  has  a 
double  effect,  it  by  drawing  the  caput  back  fills  up  the  front  of  the 
neck  of  the  bladder;  and  by  easing  the  orifices  of  the  ductus  ejacu-. 

* Diseases  of  the  Urethra,  &e.,  p.  10.  Lond.  1820. 

f Anat.  Atlas,  Fig.  373  from  preparations  in  Anatomical  Museum,. 

'p  Chapman’s  Med.  and  Phys.  Journ.  1824. 


104 


URINARY  ORGANS. 


latorii  allows  a free  exit  of  semen,  while  it  prevents  the  latter  from 
retrograding  into  the  bladder. 

Occasionally  there  exist  on  each  side  of  the  neck  of  the  bladder, 
passing  from  it  to  the  pubes,  a muscle  of  half  an  inch  in  breadth, 
the  effect  of  which  is  to  draw  the  neck  of  the  bladder  towards  the 
symphysis  pubis.  This,  called  by  some  the  muscle  of  Wilson,  or 
the  Compressor  Urethrae  has  also  an  influence  in  retaining  the  urine. 
When  it  exists  in  a distinct  state  it  is  evidently,  the  anterior  fasci- 
culus more  detached  than  usual  of  the  Levator  Ani;  but  under  ordi- 
nary circumstances  it  appears  as  the  anterior  margin  of  that  muscle, 
and  therefore  does  not  attract  especial  attention. 

As  the  urethra  of  the  male  performs  the  double  office  of  conducting 
both  semen,  and  urine,  it  will  be  described  more  properly  along  with 
the  organs  of  generation. 

The  urine  has  a considerable  number  of  constituents,  the  propor- 
tion of  which  varies  according  to  age,  health,  and  other  circumstan- 
ces. Water  forms  about  nine-tenths  of  it,  the  remainder  is  an  animal 
matter  insoluble  in  alcohol;  uric  and  lactic  acids;  lactate  of  am- 
monia; sulphate  of  potash  and  of  soda;  hydrochlorate  of  soda  and 
pf  aminonia ; phosphate  of  soda  pnd  of  lime ; and:  fluate  of  lime. 


ORGANS  OF  GENERATION. 


CHAPTER  I. 

Of  the  Organs  of  Generation  in  the  Male. 

The  Male  Organs  of  Generation  consist  in  the  Testicles  and  in 
the  Penis,  with  their  appendages ; or,  in  the  language  of  some  anato- 
mists, in  the  Formative  and  in  the  Copulative  Organs  ; which  dis- 
tinction has  been  applied  to  both  sexes. 


SECT.  I. — OF  THE  PENIS.* 

The  Penis,  ( Membrum  Virile , Mentulay)  from  performing  the  two* 
offices,  one  of  which  is  the  conducting  of  urine  from  the  bladder,, 
and  the  other  the  projection  of  semen  into  the  female,  has  accord- 
ingly, a peculiarity  of  structure,  which  allows  a state  of  collapse  and 
of  erection.  Its  shape  is  almost  cylindrical,  but  terminating  in  front 
by  an  obtusely  pointed  extremity,  named  Gians.  It  adheres  by  its 
posterior  end  or  root  to  the  bones  of  the  pelvis,  at  and  below  the 
symphysis  pubis. 

It  is  formed  by  common  integuments,  by  condensed  cellular  tissue,, 
by  the  Corpus  Cavernosum,  and  by  the  Corpus  Spongiosum. 

The  skin  on  tire  penis  is  more  thin  and  delicate  than  it  is  on  most 
other  parts  of  the  body,  and  is  furnished  with  a considerable  number 
of  sebaceous  follicles  or  glands  about  the  root  of  the  organ,  with 
hairs  growing  from  the  centre  of  them.  This  same  skin,  in  passing. 

* Anat.  Atlas.  Fig.  376  to  381,  inclusive. 

10* 


106 


ORGANS  OF  GENERATION. 


to  the  abdomen  over  the  pubes,  is  somewhat  protruded  by  a subja- 
cent deposite  of  fat  and  cellular  matter,  causing  an  appearance  cor- 
responding w’ith  the  mons  veneris  of  the  female  ; and  is  also  generally 
thickly  covered  with  short  curly  hair,  which,  as  the  individual  ad- 
vances in  life,  proceeds  in  a pointed  direction  to  the  umbilicus.  The 
skin  of  the  penis  is  connected  to  the  organ  by  a loose  filamentous 
cellular  substance,  so  that  it  slides  readily  backwards  and  forwards, 
and  by  its  elasticity  is  well;  suited  to  the  varying  states  of  erection 
and  collapse.  At  the  anterior  extremity  it  is  thrown  into  a dupli- 
cature  or  fold,  the  prepuce,  (Prceputium ;)  the  internal  lamina  of 
which  being  fixed  circularly  to  the  penis,  some  distance  back  from 
the  point,  permits  a considerable  portion  of  that  extremity  of  the 
penis,  called  the  Gians,  to  project  when  the  prepuce  is  drawn  back. 
The  under  middle  part  of  the  prepuce  is  attached  to  the  extremity  of 
the  glans  by  a vertical  longitudinal  duplicature,  called  the  Frsenum, 
which  extends  to  the  orifice  of  the  urethra, 

The  skin  does  not  actually  stop  at  the  circumference  of  the  glans, 
but  is  continued  smoothly  over  it,  modified,  however,  so  much  in 
its  structure,  as  to  be  much  more  adherent,  soft,  delicate,  vascular, 
and  sentient:  its, cuticle  tlier.e  is  a thin  epithelium,  readily  separated 
by  maceration.  The  projecting  circular  and  oblique  shoulder  of  the 
glans,  behind  which  the  skin. becomes  firmly  joined  to  the  penis,  is 
called  the  Crown  ( Corona  Glandis .)  The  contracted  portion,  behind 
the  corona,  is  the  Neck  ( Colhim .)  On  the  surface  of  the  neck  and 
the  posterior  face  of  the  corona,  the  skin  is  furnished  with  an  abun- 
dance of  small  glandular  masses  or  follicles,  ( Glandules.  Odoriferce 
Tysoni,)  which,  secrete  the  thick  white  sebaceous  matter,  (Smegma 
\ preeputii ,)  that  accumulates  w’hen  personal  cleanliness  is  not  attend- 
ed to. 

The  penis,  in  addition  to  other  modes  of  attachment  to  the  bones 
of  the  pelvis,  is  fixed  by  the  Ligamentum  Suspensorium.  The  latter 
is  a triangular  vertical  fibrous  lamina,  which  proceeds  dowmwards 
from  the  symphysis  pubes  to  the  dorsum  of  the  penis;  and,  accord- 
ing to  Mr.  Codes,  envelops  this  organ  to  the  glans,  forming  its  cel- 
lular coat,  and  being  continued  into  the  fascia  superficialis  abdo- 
minis. This  cellular  coat  is  found  sometimes  in  no  small  degree 
condensed  in  its  texture  and  fibrous,  so  that  it  becomes  a sort  of 
fascia.  Posteriorly,  it  is  lost  insensibly  on  the  fascia  of  the  thighs, 
covering  the  adductor  muscles.  At  its  origin  it  is  occasionally 


THE  PENIS. 


107 


furnished  with  muscular  fibres;  one  strongly  marked  instance  of 
which  has  been  presented  to  me  in  my  own  dissections. 

The  Corpus  Cavernosum  of  the  penis,  forms  by  much  the  most 
considerable  portion  of  the  whole  organ.  Externally,  it  is  a white 
fibrous  membrane,  of  a dense  structure,  enjoying  extensibility  and 
an  extreme  degree  of  contractility.  This  coat  of  the  penis  is  occa- 
sionally called  its  elastic  ligament.  Its  external  fibres  pass,  for  the 
most  part,  longitudinally,  except  about  the  root,  where  they  are 
blended  with  the  periosteum  of  the  bone,  and  with  the  tendons  of 
the  muscles.  It  arises  by  two  conical  crura,  swollen  at  their  base, 
from  the  internal  face  of  the  crura  of  the  pubes  and  ischia,  to  within 
a little  distance  of  the  anterior  part  of  the  tuber  ischii.  At  the  lower 
part  of  the  symphysis  pubis  these  crura  join  and  form  a body  ; which, 
when  stripped  of  its  connexions,  resembles  two  cylinders  united, 
lying  alongside  of  each  other;  and  which  terminate  in  common,  an- 
teriorly, by  a truncated  cone,  covered  obliquely  by  the  glans.  At 
the  posterior  part  of  the  corpus  cavernosum,  in  its  centre,  there  is 
a septum,  almost  complete,  also  of  the  same  elastic  substance,  which 
separates  the  two  halves  from  each  other;  but,  anteriorly,  this  septum 
is  more  imperfect,  having  an  arrangement  like  the  teeth  of  a comb, 
whence  the  term  Septum  Pectiniforme  has  been  given  it.  This  sep- 
tum is  continued  at  its  margins  into  a layer  of  circular  fibres,  con- 
stituting the  internal  coat  of  the  corpus  cavernosum.  In  this  arrange- 
ment into  external  longitudinal  and  internal  circular  fibres,  we  see  a 
renewal  of  the  same  mechanism  which  marks  the  hollow  viscera. 
It  is  commonly  not  noticed  by  anatomists. 

In  the  middle  of  the  corpus  cavernosum,  above,  is  a longitudinal 
depression  for  lodging  the  veins  of  the  penis,  and,  in  the  same  man- 
ner, there  is  another  below,  for  the  corpus  spongiosum  urethrae. 
The  cavity  of  this  membrane  is  filled  by  a spongy  tissue,  that  arises 
frorn  its  internal  face,  and  is  formed  of  filaments  and  little  laminae ; 
they,  by  crossing  each  other,  make  a multitude  of  cells,  which  have 
a perfectly  free  communication  with  one  another,  and  generally  are 
somewhat  occupied  by  blood.  A fine  injection  through  the  artery 
of  the  corpus  cavernosum  will  fill  these  cells  and  return  through 
the  veins ; from  which  cause  the  cells  may  be  considered  as  inter- 
mediate to  the  two  orders  of  vessels.  This  opinion  is  the  more 
probable  from  the  cells  being  lined  by  a thin  membrane  like  the  in- 


108 


ORGANS  OF  GENERATION. 


ternal  one  of  the  veins,  and  which  is  easily  seen  near  the  septum  by 
tearing  the  spongy  part  from  it. 

The  internal  cellular  structure  of  the  corpus  cavernosum  is  pro- 
bably formed,  almost  exclusively,  by  the  internal  coat  of  the  dilated 
veins,  partially  sustained  by  the  above  filamentous  and  laminated 
bands,  for  the  purpose  of  strengthening  the  arrangement.  The  ad- 
hesion of  this  structure  at  large  to  the  corpus  cavernosum  is  much 
weaker  than  one  may  suppose,  as  it  is  very  easy  to  peel  or  roll  it  off' 
almost  without  dissection,  thus  leaving  the  elastic  ligament  of  the 
corpus  cavernosum  perfectly  free.  In  the  case  of  the  corpus  spon- 
giosum, the  cellular  structure,  though  analogous  in  texture  to  the 
above,  does  not  peel  off  so  easily. 

The  Corpus  Spongiosum  Urethrae  extends  from  ten  or  twelve  lines 
behind  the  junction  of  the  crura  of  the  corpus  cavernosum,  to  the 
anterior  extremity  of  the  penis.  Externally,  it  has  a coat  resembling 
that  of  the  corpus  cavernosum,  except  that  if  is  thinner,  and  in  its 
centre  is  the  canal  for  the  passage  of  urine.  Between  the  canal  and 
the  coat  is  a spongy  structure,  much  finer  than  that  of  the  corpus 
cavernosum,  and  though  the  cells  communicate  freely,  still  they  have 
the  appearance  of  convoluted  veins.  The  corpus  spongiosum  is  not 
of  equal  diameter  in  its  whole  course,  for  its  commencement  in  the 
perineum,  where  it  is  pendulous,  is  enlarged  into  what  is  termed  the 
Bulb;  from  this  it  diminishes  gradually  to  the  anterior  end,  where 
it  is  again  enlarged  into  the  glans  penis. 

Fig.  29.  Midler*  has  made  the  assertion  that  there  are  two 

modes  of  arterial  termination  in  this  erectile  or  cel- 
lular structure  of  the  penis,  one  by  direct  connexion 
with  the  incipient  ramuscles  of  the  veins,  and  the 
other,  by  tufts  of  cceca  bent  backwards  on  them- 
selves, as  here  represented,  and,  which  he  has  named 
Helicine  arteries  (Arter.  llelicinse. ) Projecting  as  they  do  into  the 

* Elem.  Physiol,  vol.  i.,  p.  252.  Lond.,  1840. 

Prof.  Valentin  (Muller’s  Archiv.  1838.  p.  182)  denies  the  existence  of  the 
arteri®  helicin®.  According  to  his  observation  all  the  branches  of  the  arteries 
of  the  corpus  cavernosum,  after  forming  numerous  anastomoses  terminate  in 
the  large  veins  of  the  penis.  The  small  arteries  run  in  the  centre  of  the  bundles 
of  fibres  which  lie  between  tbe  veins  ; and  when  these  bundles  of  fibres,  or 
band-like  septa,  are  cut  or  torn  across,  they,  together  with  the  arterial  twigs 
within  them,  contract  and  assume  a contorted,  sometimes  spiral  figure.  In 


THE  PENIS. 


109 


venous  cells,  he  declares  that  though  no  openings  from  them  can  be 
discovered,  yet  the  latter  exist  so  as  to  fill  the  cells  in  erection. 
These  singular  arteries  are  found  principally  in  the  back  part  of  the 
corpus  cavernosum  and  spongiosum,  and  are  seen  after  a minute 
size  injection  of  the  arteries  of  the  penis,  by  washing  the  size  from 
the  cells,  when  the  cells  have  been  filled. 

The  Urethra  is  a mucous  canal,  whose  length  varies  according  to 
the  degree  of  erection  in  the  penis,  and  extends  from  the  neck  of  the 
bladder  to  the  extremity  of  the  glans.  It  is  difficult  to  assign  a 
fixed  length  to  the  canal  of  the  urethra,  owing  to  the  variable  size 
of  the  penis  in  different  persons,  and  in  the  same  individual,  depend- 
ing upon  his  general  vigour  and  also  period  of  life.  The  measurements 
of  Professor  Pancoast'*  in  the  black  and  mulatto,  show  an  average  of 
about  seven  inches  from  the  neck  of  the  bladder  to  the  end  of  the 
urethra  in  the  unstretched  state,  and  about  an  inch  more  in  stretch- 
ing the  organ  moderately.  It  is,  however,  well  known  that  the 
sexual  organs  of  the  black  are  larger,  both  male  and  female,  than  of 
the  white. 

The  urethra  is  curved,  and  receives  in  its  course  the  ductus 
ejaculatorii,  the  excretory  ducts  of  Couper’s  glands,  and  the  mucous 
lacunse  of  its  own  internal  membrane.  The  first  part  of  this  canal 
which  traverses  the  prostate  gland  is  from  fifteen  to  eighteen  lines 
in  length,  and  is  called  the  Prostatic  Portion : it  is  well  supported  by 
this  body,  although  its  own  sides  are  very  thin.  On  its  inferior  sur- 
face is  the  doubling  which  constitutes  the  Verumontanum  or  Caput 
Gallinaginis.  On  either  side  of  the  caput  gallinaginis  the  canal  of  the 
urethra  is  depressed  into  something  like  an  oblong  cul-de-sac  or 
narrow  trench,  where  are  to  be  found  the  lacunae  of  the  prostate 
gland. 

Between  the  Prostate  and  the  Bulb  is  the  membranous  part  of  the 
urethra,  about  eight  or  ten  lines  long ; it  is  unprotected,  except  by 

this  state  they  form  the  so-called  arteri®  helicinse.  The  fibrous  bands  which 
pass  inwards  between  the  anastomosing-  veins  from  the  external  tunic  of  the 
corpus  cavernosum,  consist,  according  to  Prof.  Valentin,  of  tendinous  tissue, 
and  give  attachment  to  muscular  fibres,  similar  to  those  of  the  intestinal  canal, 
which  pass  from  them  to  the  parietes  of  the  veins.  M.  Valentin  supposes  erec- 
tion to  be  in  a great  measure  due  to  the  active  dilatation  of  the  veins  by  these 
muscular  fibres ; but  the  characters  on  which  he  founds  his  belief  that  the 
fibres  in  question  are  muscular,  are  not  conclusive. 

* Wistar’s  Anat.  8th  Edit.,  vol.  ii.  p,  170. 


110 


ORGANS  OF  GENERATION. 


a soft  covering,  which  seems  in  some  measure  to  be  a mixture  of 
gelatinous  matter  and  muscular  fibre.  The  former  wTas  considered 
by  Littre  as  a glandular  body  which  secreted  a viscid  humour  into 
the  interior  of  the  canal ; the  latter,  probablv,  is  the  part  described 
by  Winslow  as  the  inferior  prostatic  muscle ; which  he  asserted  to 
arise  on  each  side  of  the  membranous  part  of  the  urethra,  and  to  be 
inserted  into  the  corresponding  branch  of  the  pubes  near  the  sym- 
physis. The  membranous  part  of  the  urethra  does  not  get  into  the 
end  of  the  bulb  but  penetrates  it  from  above,  half  an  inch  or  more 
occasionally,  from  its  extremity,  just  below  the  junction  of  the  crura 
of  the  corpus  cavernosum. 

The  canal  varies  in  its  diameters:  at  its  commencement,  which  is 
synonymous  with  the  neck  of  the  bladder,  it  is  large  ; it  then  con- 
tracts at  the  back  of  the  caput  gallinaginis,  and  immediately  en- 
larges in  the  fore  part  of  the  prostate,  at  the  sides  of  the  caput. 
The  membranous  part  is  small ; the  canal  then  enlarges  in  the  bulb. 
In  the  body  of  the  penis  the  canal  is  successively  diminished,  till  it 
comes  almost  to  the  glans,  when  it  is  so  remarkably  enlarged  again 
as  to  get  the  name  of  Fossa  Navicularis  ; it  terminates,  finally,  by  a 
short  vertical  slit  at  the  extremity  of  the  glans. 

The  canal  of  the  urethra  is  formed  of  a very  thin  mucous  mem- 
brane, on  the  outside  of  which  is  a dense  filamentous  cellular  sub- 
stance possessing  much  extensibility,  contractility  and  elasticity. 
The  mucous  membrane  has  great  vascularity,  and  its  veins  are  so 
superficial  that  they  frequently  bleed  freely  upon  the  introduction  of 
an  instrument  into  the  bladder,  it  is  also  very  sensitive.  The  cel- 
lular coat  on  its  outside,  whereby  it  adheres  to  the  spongy  structure, 
contracts  sometimes  in  such  a manner  that  circular  fasciculated 
ridges  simulating  the  presence  of  circular  muscular  fibres,  are  seen 
shining  through  the  mucous  coat,  though  when  the  mucous  coat  is 
peeled  off  this  arrangement  disappears. 

In  the  whole  length  of  the  canal  there  are  two  folds  or  lines,  one 
above,  and  the  other  below ; and  in  the  membranous  and  spongy 
portions,  excepting  the  fossa  navicularis,  longitudinal  folds  of  the 
mucous  membrane  also  exist,  which  are  effaced  by  distention. 
The  fossa  navicularis  sometimes  exhibits  in  the  contracted  penis, 
hardened  in  spirits  of  wine,  very  superficial  folds  of  the  mucous 
membrane  almost  transverse,  in  the  narrow  depressions  between 
which  we  see  the  orifices  of  very  fine  mucous  follicles. 

In  the  upper  part  of  the  canal  there  are  a great  many  mucous 


« 


THE  PENIS. 


Ill 


lacunae  ;* * * §  Loder  has  marked  about  sixty-five : there  is  one  parti- 
cularly large  in  the  upper  surface  of  the  fossa  navicularis,  which,  it 
is  said,  has  stopped  the  point  of  a bougie,  and  been  mistaken  for 
stricture.! 

Mr.  Shaw  has  described  a set  of  vessels  immediately  on  the  out- 
side of  the  internal  membrane  of  the  urethra ; which  when  empty, 
are  very  similar  in  appearance  to  muscular  fibres.  He  says,  he  has 
discovered  that  these  vessels  form  an  internal  spongy  body,  which 
passes  down  to  the  membranous  part  of  the  urethra,  and  forms  even 
a small  bulb  there.!  His  preparation,  being  a quicksilver  injection 
of  the  part,  is  certainly  a very  satisfactory  demonstration  of  its  exist- 
ence ; yet  in  my  own  observations,  where  the  blow-pipe  has  been 
resorted  to,  it  has  rather  appeared  to  me  to  be  the  cellular  membrane 
connecting  the  canal  of  the  urethra  with  the  corpus  spongiosum. 

The  arteries  of  the  penis  come  from  the  internal  pudic;  some  of 
its  veins  follow  the  course  of  the  arteries,  and  others  collect  into  the 
two  vente  dorsales  penis;  the  nerves  come  from  the  Superior  and 
Inferior  Pudendal. 


SECT.  II. — OF  THE  MUCOUS  GLANDS  AND  APPARATUS. 

The  Seminal  Vesicles§  ( Vesiculce  Seminales ) are  two  convoluted 
tubes,  one  on  each  side,  two  inches  in  length,  placed  on  the  lower 
fundus  of  the  bladder,  between  it  and  the  rectum,  and  behind  the 
prostate  gland.  At  their  anterior  extremities  they  approach  very 
nearly  to  each  other,  being  only  separated  by  the  intervention  of 
the  vasa  deferentia.  They  are  fixed  to  the  bladder,  and  surrounded 
by  a thick  mass  of  adipose  and  cellular  matter,  with  many  blood 
vessels,  principally  veins,  passing  through  it. 

When  inflated  and  dried,  they  present  the  semblance  of  cells, 
but  are,  in  fact,  long  tubes;  which  being  convoluted,  are  reduced 
to  the  apparent  dimensions  mentioned.  When  dissected  and 

* Tabula  Anat. 

t Sir  Everard  Home  formerly  communicated  to  the  Royal  Society  a highly 
interesting  paper  on  the  structure  of  the  lining  membrane  of  the  urethra.  From 
his  microscopical  observations  he  was  induced  to  think  that  it  is  muscular. 

! Med.  Chir.  Trans,  vol.  X. 

§ Anat.  Atlas,  Figs.  383,  390,  391,  392._ 


112 


ORGANS  OF  GENERATION. 


stretched  out,  they  are  four  or  five  inches  long,  by  three  lines  in 
diameter. 

There  are  also  several  pouches  on  each  side  of  the  long  tube 
which  increase  the  number  of  cells.  The  convolutions  are  pre- 
served by  the  intermediate  cellular  tissue.  These  bodies  consist  of 
two  coats:  an  external,  which  is  a condensed  fibro-cellular  sub- 
stance; and  an  internal,  which  is  mucous,  being  a continuation  of 
the  lining  membrane  of  the  urethra.  The  excretory  duct  of  each 
vesicle  is  about  a line  and  a half  long,  when  it  joins  in  the  sub- 
stance of  the  prostate  with  the  vas  deferens  of  the  same  side;  a 
common  canal  ( ductus  ejaculatonus ) is  thus  formed,  which  runs 
parallel  with  its  fellow,  below  the  urethra.* 

The  Ductus  Ejaculatorius  is  about  eight  or  ten  lines  long,  and 
opens  by  an  oblong  orifice,  on  the  anterior  margin  of  the  Caput 
Gallinaginis;  it  is  larger  behind  than  before,  which  gives  it  a conical 
shape,  and  allows  fluids  injected  to  pass  freely  from  the  vas  deferens 
to  the  vesicula  seminalis,  and  the  reverse. 

The  vesiculte  are  commonly  filled  by  a drab-coloured  thick  fluid, 
supposed  to  be  a mixture  of  the  semen,  with  their  own  proper  se- 
cretion, though,  of  this,  Mr.  Hunterf  doubted,  inasmuch  as  he  found 
them  equally  well  filled  in  cases  where  the  testicle  of  the  corres- 
ponding side  had  been  lost,  and  therefore  he  concluded  that  they 
were  not  indebted  to  the  secretion  of  the  testicle  for  their  contents. 
The  discovery,  latterly,  of  spermatic  animalcules  in  the  fluid  con- 
tained after  death  in  the  vesiculas  is  considered  now  as  proof  suffi- 
cient of  their  being  reservoirs  of  the  male  semen  along  with  their 
own  secretion,  as  these  animalcules  were  most  probably  conveyed 
there  along  with  the  semen. 

The  Prostate  Gland  ( Glandula  Parastata ) is  a body  about  the 
size  and  form  of  a horse  chestnut,  fixed  on  the  neck  of  the  bladder, 
and  penetrated  by  the  urethra,  which  traverses  it  much  nearer  its 
superior  than  its  inferior  surface.  The  base  of  it  is  turned  back- 
wards, and  the  point  upwards;  its  inferior  surface  rests  upon  the 

* In  a dissection  executed  at  the  University  by  Dr.  Joseph  Togno,  a muscle 
was  found  on  the  inferior  surface  of  the  seminal  vesicles  arising  from  the  pros- 
tate gland,  and  inserted  into  them.  This  is  said  to  be  a common  arrangement 
in  some  animals. 

f Observations  on  the  Animal  Economy. 


PROSTATE  GLAND. 


113 


rectum ; it  is  rendered  concave  by  that  circumstance,  and  its  sides, 
in  the  distentions  of  this  organ  by  faeces,  are  overlapped  by  it.  The 
Prostate  has,  posteriorly,  a notch  in  its  centre,  which  divides  it  into 
two  lateral  lobes,  and  by  raising  the  Vesiculae  Seminales,  we  see 
where  their  excretory  ducts  penetrate  the  gland,  and  separate  from 
the  body  of  it,  the  little  tubercle,  to  which  Sir  Everard  Home*  has 
particularly  called  the  attention  of  the  profession,  and  considered 
as  a third  Lobe ; it  being  certain  that  it  is  frequently  the  seat  of  dis- 
ease and  tumefaction. 

On  the  under  surface  of  the  canal  formed  in  the  prostate,  by  the 
urethra,  is,  as  mentioned,  the  oblong  elevation  called  the  Verumon- 
tanum,  or  Caput  Gallinaginis.  It  commences  a little  in  front  of  the 
uvula  vesicas,  and,  being  broader  and  higher  behind,  comes  to  a 
point  very  gradually  before;  it  is  about  eight  or  ten  lines  long. 
Along  the  posterior  part  of  this  ridge  a long  cleft  is  sometimes 
found,  it  being  the  orifice  of  a lacuna,  first  observed  by  Morgagni ; 
and  in  front  are  the  orifices,  bordering  upon  each  other,  of  the  ductus 
ejaeulatorii.  Very  superficial  folds  of  the  lining  membrane,  some 
three  or  four  in  number,  radiate  from  the  anterior  end  of  the  caput 
to  the  anterior  end  of  the  membranous  portion  of  the  urethra.  The 
use  of  the  Caput  Gallinaginis,  as  already  intimated,  is  probably  to 
plug  the  orifice  of  the  urethra  at  the  neck  of  the  bladder,  at  the 
moment  of  ejecting  the  semen:  it  being  drawn  backwards  to  that 
effect  by  the  muscle  of  the  vesical  triangle. 

The  prostate  consists  in  a condensed,  white,  extensible,  though 
easily  lacerated  fibrous  cellular  tissue,  within  which  are  placed  a 
great  number  of  mucous  canals,  that  have  from  eight  to  twelve 
ducts,  or,  according  to  Loder,  from  thirty-two  to  forty-four,  passing 
obliquely  forwards,  and  terminating  in  the  urethra,  as  stated,  at  the 
sides  of  the  urethral  crest,  or  caput  gallinaginis.  It  is  an  aggrega- 
tion of  smaller  glands,  like  the  mamma  or  any  other  composite 
gland ; the  principal  ducts  are,  therefore,  formed  by  the  convergence 
of  branches  in  successive  junction.  The  fluid  secreted  is  thick, 
ropy,  white,  and  semi-transparent,  in  a healthy  state.  The  prostate 
is  surrounded  by  a fibrous  capsule,  to  be  described. 

The  lacunae  of  the  third  lobe  penetrate  the  coats  of  the  bladder, 
behind  the  caput  gallinaginis. 

* Diseases  of  Prostate. 

VOL.  II.— 11 


114 


ORGANS  OF  GENERATION. 


Of  the  Glands  of  Couper. — These  glands  are  also  intended  for 
the  secretion  of  mucus,  or  a fluid  very  much  like  it,  into  the  canal 
of  the  urethra.  They  are  two  in  number,  one  on  each  side,  and 
are  situated  in  advance  of  the  prostate,  between  the  laminte  of  the 
triangular  ligament,  at  the  point  where  the  bulb  of  the  urethra  ad- 
heres to  it.  Commonly,  they  are  about  the  size  of  a garden  pea, 
but  not  unfrequently  much  smaller,  and,  in  some  instances,  cannot 
be  found  at  all,  which  induced  Hiester  to  declare,  that  he  had 
searched  for  them  fruitlessly.  They  are  yellowish,  hard,  and  con- 
sist of  several  lobules  united  together.  Each  one  has  an  excretory 
duct,  that  receives  readily  a bristle,  and  passes  obliquely  forwards, 
between  the  corpus  spongiosum  and  the  canal  of  the  urethra,  to  ter- 
minate in  an  oblique  orifice  in  the  latter,  about  an  inch  distant  from 
the  gland. 

One  or  more  glands,  of  the  same  description,  and  discovered  by 
Littre,  are  occasionally  found  just  in  front  of  Couper’s.  They  also 
discharge  their  secretion  into  the  adjacent  part  of  the  urethra.  In 
my  own  dissections  I have  not  met  with  them. 


SECT.  IIJ. — OF  THE  TESTICLES.* 

The  Testicles  ( Testes , Didymi)  are  two  in  number,  one  for  each 
side  of  the  scrotum.  Being  the  seat  of  the  secretion  of  sperm  or 
the  male  prolific  liquor,  their  function  is  of  the  first  importance  in 
the  act  of  generation.  They  are  of  an  oblong  oval  form,  somewhat 
compressed  laterally  ; and  present  their  edges  forward  and  back- 
ward. From  being  suspended  near  the  middle  of  their  posterior 
edge  by  the  spermatic  cord,  the  upper  end  points  somewhat  forward, 
while  the  lower  one  is  directed  in  the  same  degree  backward.  They 
are  about  an  inch  and  a half  long,  by  one  inch  in  breadth,  and  eight 
or  nine  lines  in  thickness.  They  are  of  equal  size  generally,  but  in 
case  of  a difference  it  is  in  favour  of  the  right ; the  latter  is  also  re- 
markable for  being  suspended  higher  than  the  left,  a feature  in  ancient 
statuary,  so  universal,  as  to  prove  the  vigilance  and  accuracy  of  the 
sculptors  of  those  days,  in  regard  to  the  proportions  and  peculiarities 
of  the  human  form.  “Two  obvious  advantages  attend  this  arrange- 
ment: one,  that  of  dhe  testicles  passing  each  other  without  col- 

* Anat.  Atlas,  Figs.  386  to  395,  inclusive. 


THE  TESTICLES. 


115 


lision  when  the  thighs  are  brought  together  ; and  another,  the  facility 
of  keeping  the  penis  to  one  side,  instead  of  straight  forward  in  the 
middle  line  of  the  body.”* 

The  testicle  is  enveloped  by  several  tunics;  they  are  the  Scrotum, 
the  Dartos,  the  Tunica  Vaginalis,  and  the  Tunica  Albuginea. 

The  Scrotum  is  merely  a continuation  of  the  common  skin  from 
the  inner  side  of  the  thighs,  the  perineum,  and  the  penis,  and  is 
common  to  the  two  testicles.  It  is  a symmetrical  bag,  and  the  two 
halves  are  marked  off  from  each  other  by  a middle  line  or  elevation 
of  the  skin,  called  the  Raphe,  which  begins  in  the  perineum  at  the 
anus,  and,  winding  around  the  scrotum,  is  continued  along  the  under 
surface  of  the  penis  to  the  prepuce. 

The  skin  of  the  scrotum  is  thin,  darker  than  elsewhere,  but  has 
a thick,  strong  epidermis;  it  has  many  sebaceous  follicles  in  it, 
and  is  sparingly  furnished  with  hair.  It  is  very  extensible,  as 
manifested  in  fatigue,  and  by  hydrocele;  and  maybe  contracted 
again  so  as  to  draw  the  testicles  close  under  the  pubes,  though  for 
the  latter  power  it  principally  depends  upon  the  subjacent  coat. 
Its  surface  is  covered  with  wrinkles,  for  the  most  part  transverse, 
and  ending  at  the  raphe : they  are  effaced  during  its  great  dis- 
tentions in  hernia  and  dropsy,  and  then  it  has  a smooth  shining 
surface. 

The  Dartos  is  placed  within  the  scrotum,  and  forms  two  distinct 
sacs  or  tunics,  one  for  each  testicle.  It  arises  from  the  inferior 
margins  of  the  crura  of  the  ischia  and  of  the  pubes,  and  lines  the 
scrotum  till  it  reaches  the  raphe  ; it  is  then  reflected  upwards  to 
form  the  partition  between  the  testicles,  ( septum  scroti ,)  and  ter- 
minates at  the  corpus  spongiosum  urethra.  This  membrane,  ac- 
cording to  the  observations  of  MM.  Chaussier,  Lobstein,  and 
Breschet,f  does  not  exist  in  the  scrotum  till  the  descent  of  the  tes- 
ticle, and  then  appears  to  be  an  expansion  of  the  gubernaculum 
testis. 

It  receives  a considerable  number  of  blood  vessels,  which,  owing 
to  the  thinness  of  the  skin,  may  be  seen  in  the  living  body,  ramify- 
ing through  its  substance:  its  general  appearance  is,  therefore, 

* Sir  A.  Cooper  on  the  Testis.  1830. 
f Dictionnaire  des  Sciences  Med.,  tome  viii. 


116 


ORGANS  OF  GENERATION. 


reddish.  It  is  destitute  of  fat,  and  consists  in  long  fibres  much 
matted  together,  and  passing  in  every  direction:  they  are  easily 
separated  by  distention  with  air  or  water,  and  by  slight  maceration. 
Its  powers  of  contraction  are  exceedingly  well  marked  upon  the 
application  of  cold  to  the  scrotum,  from  which  cause  it  has  been 
considered  by  many  anatomists  as  muscular:  the  only  distinct  evi- 
dence, however,  which  I have  met  with  of  a resemblance  to  the 
latter,  has  been  found  generally  on  its  posterior  face,  near  the 
perineum  * From  its  equivocal  character,  J.  F.  Meckel  has  very 
ingeniously  suggested  that  it  forms  the  transition  from  cellular  to 
muscular  tissue,  and  that  there  exists  between  it  and  other  muscles 
the  same  relation  that  there  is  between  the  muscles  of  the  superior 
and  of  the  inferior  orders  of  animals.  Among  the  latter,  the  fibrous 
structure  is  indistinctly  marked,  and  is  masked  by  gelatine,  an  ele- 
ment of  the  cellular  tissue ; which  envelops  and  conceals  the  fibrine, 
an  element  of  the  muscular  tissue. 

The  fibres  of  the  cremaster  muscle,  which  are  next  in  order, 
form  a very  imperfect  covering  to  the  testicle,  and  belong  rather 
to  the  spermatic  cord : what  remains  to  be  said  concerning  them 
will  be  more  properly  introduced  into  the  account  of  the  latter. 
The  cellular  substance  that  connects  the  dartos  and  the  cremaster 
with  the  tunica  vaginalis  forms  a compact  and  perfect  lamina, 
sometimes  spoken  of  as  the  Tunica  Vaginalis  Communis  Testis. 
There  is  one  for  each  testicle,  which  it  surrounds  entirely,  as  well 
as  its  chord,  and  connects  the  chord  to  the  margin  of  the  external 
abdominal  ring,  as  stated  in  the  account  of  the  latter.  At  its  upper 
end  it  is  continuous  with  the  cellular  substance  that  unites  the  peri- 
toneum to  the  parietes  of  the  abdomen,  as  may  be  proved  by  in- 
flating it,  when  the  air  will  penetrate  accordingly  through  the  ab- 
dominal canal. 

The  Peritestis,  or  Tunica  Vaginalis,  was  originally  a process  of 
peritoneum,  communicating  with  the  cavity  of  the  latter  through 
the  abdominal  canal ; but  in  the  adult,  it  appears  as  a complete 
and  distinct  sac.  As  it  is  very  rigidly  comparable  to  a double 
night-cap  drawn  over  the  head,  we  accordingly  find  that  the  testi- 

* Since  the  first  edition,  I have  dissected  one  subject,  (January,  1830,) 
where  the  fibres  were  evidently  muscular,  though  interwoven. 


THE  TESTICLES. 


117 


cle,  along  with  the  epididymis  is  pushed  into  it  from  behind.  That 
portion  of  the  tunica  vaginalis  which  is  in  contact  with  the  testicle, 
or  rather  with  the  tunica  albuginea,  adheres  so  closely  that  it  can- 
not be  separated,  except  very  partially  and  in  shreds;  but  it  may 
be  detached  easily  from  the  epididymis,  with  the  convolutions  of 
which  it  is  in  immediate  contact.  This  sac  is  longer  and  larger 
than  the  testicle  itself,  from  which  cause  it  ascends  for  several  lines 
above  the  superior  end  of  the  gland,  and  the  free  part  hangs  loosely 
about  it.  Its  cavity  may,  with  but  little  force,  be  injected  so  as  to 
hold  an  ounce  or  two  of  fluid. 

This  membrane  is  smooth  and  polished  on  the  surface  forming 
its  cavity,  and  contains  a small  quantity  of  serous  halitus,  which 
allows  the  opposed  surfaces  to  glide  freely  upon  one  another.  Its 
exterior  connexion  with  the  dartos  is  so  slight  that  it  may  be  with- 
drawn without  dissection,  with  the  exception  of  an  adhesion  at  the 
lower  end  of  the  testis  arising  from  the  remains  of  the  guberna- 
culum : in  such  case,  however,  it  still  continues  to  be  invested  by 
the  tunica  vaginalis  communis,  from  which  it  can  only  be  removed 
by  a special  dissection. 

The  Tunica  Albuginea  is  the  proper  coat  of  the  testicle;  is  in  im- 
mediate contact  with  its  glandular  structure,  and  serves  to  maintain 
its  shape,  as  well  as  to  protect  it  from  pressure.  From  its  interna^ 
surface  proceed  many  membranous,  horizontal  fibres,  which  form 
partial  partitions  of  its  cavity  ( Septulce  Testis)  and  incline  towards 
its  posterior  part,  where  they  terminate  in  a longitudinal  projection, 
called  Corpus  Highmorianum.  The  latter  is  of  a prismatic  shape, 
somewhat  broader  above  than  below,  and  is  of  but  little  consequence, 
except  that  it  was  once  erroneously  supposed  to  be  a sinus,  into 
which  the  seminiferous  tubes  discharged.  Sir  Astley  Cooper  pro- 
poses to  call  this  the  mediastinum  testis,  and  considers  the  Corpus 
Highmorianum  as  being  formed  by  an  inflection  of  the  tunica  albu- 
ginea. The  Septulae  Testis,  he  asserts,  really  envelop  the  semini- 
ferous tubes,  by  forming  bags  which  support,  confine,  protect,  and 
nourish  the  tubular  structure  of  the  testis.*  The  albuginea  is  per- 
forated by  several  foramina  along  its  posterior  margin,  where  there 
is  a deficiency  of  tunica  vaginalis,  for  the  passing  of  excretory  ducts 
and  blood  vessels. 

* Observations,  &c.  on  the  Testis,  p.  14.  London,  1830. 

11  * 


118 


ORGANS  OF  GENERATION. 


This  membrane  is  dense,  strong,  white,  and  fibrous,  resembling 
in  structure  the  tunica  sclerotica  of  the  eye,  and  the  dura  mater  of 
the  brain.  Sir  A.  Cooper  considers  the  tunica  albuginea  as  con- 
sisting of  two  layers  which  can  be  readily  separated  by  dissection, 
excepting  in  front;  the  outer  layer  is  the  fibrous  one,  while  the  in- 
ternal one,  which  he  calls  Tunica  Vasculosa,  has  the  spermatic 
arteries  and  veins  ramifying  upon  it.  They  are  rendered  very  dis- 
tinct from  each  other  by  a minute  injection.* 

Of  the  Minute  Structure  of  the  Testicle.] — The  glandular  portion 
of  the  testicle  consists  in  a congeries  of  zig-zag  tubes  ( Tubuli  Semi- 
niferi)  which  are  collected  into  lobules.  One,  two,  or  more  tubes 
constitute  a lobule,  and  the  lobules  are  kept  apart  by  the  septulae 
testis.  These  lobules  are  of  a conoidal  shape,  having  their  points 
towards  the  posterior  middle  line  of  the  Testis  and  their  bases 
rounded,  they  diverge  from  the  corpus  Highmorianum,  so  as  to  fill 
up  the  cavity  of  the  tunica  albuginea.  The  entire  number  of  tubes 
amounts  to  300,  according  to  Dr.  Munro;  with  an  aggregate  length 
of  520S  feet,  and  the  diameter  of  each  one  does  not  exceed  one  two- 
hundreth  part  of  an  inch,  and  its  length  is  somewhat  short  of  seven- 
teen and  a-half  feet.  Their  number  is,  according  to  Krause,  from 
404  to  4S4.  Lauth  has  stated  the  number  of  tubes  to  be  840,  and 
the  length  of  each  to  be  about  twenty-seven  inches,  which  corres- 
ponds nearer  with  my  own  observations,  and  makes  an  aggregate 
length  of  about  one-third  of  that  represented  by  Dr.  Munro.  These 
tubes  form  convolutions  or  hanks,  the  threads  of  which  are  serpen- 
tine, very  much  like  the  thread  of  a ravelled  stocking;  and  are  held 
together  by  a delicate  cellular  substance  easily  softened  by  macera- 
tion. Each  tube  forms  of  itself  a hank,  which  is  kept  distinct  from 
the  adjacent  ones  by  the  septulce  or  processes  of  the  albuginea,  and 
may  be  easily  picked  out  from  them.  Their  extreme  tenuity  and 
delicacy  of  structure  cause  them,  when  well  macerated,  drawn  out 
with  a pin,  and  then  suspended  in  water,  to  resemble  a tangled 
skein  of  fine  silk. 

The  tubuli  seminiferi  finally  terminate  in  some  straight  tubes, 
called  the  Vasa  Recta,  which  unite  near  the  middle  back  part  of 
the  testicle  in  a somewhat  complicated  arrangement,  obtaining  the 

* Observations,  &c.  on  the  Testis,  p.  14.  London.  1830. 

f Hunter,  Med.  Comment,  p.  1.  1777.  Albinus,  Acad.  Annot.  Lib.  ii. 
Loder,  Tab.  Anat. — Ruysch,Thes.Anat.  iv.  Haller,  Op.  Min.  tom.  ii. — Alex. 
Munro.  de  Testibus,  Ed.  1755. 


THE  TESTICLES. 


119 


name  of  the  Rete  Vasculosum  Testis.  This  Rete  Vasculosum  is 
placed  in  the  Corpus  Highmorianum  and  from  it  there  proceed  from 
twelve  to  eighteen  ducts  ( Vasa  Efferentia)  which  go  upwards  and 
backwards  through  the  corpus  Highmorianum  and  the  tunica  albu- 
ginea. Each  of  these  vasa  efferentia  is  then  convoluted  upon  itself 
into  a conical  body,  called  Conus  Vasculosus,  which  presents  its 
base  backwards.  Each  conus,  at  its  base,  has  its  tube  entering 
successively  into  the  tube  of  which  the  Epididymis  is- formed. 

Notwithstanding  the  extreme  tenuity  of  these  several  arrange- 
ments in  the  excretory  ducts  of  the  testicle,  they  may  be  entirely 
filled  with  quicksilver  from  the  vas  deferens;  but  the  task  is  one  of 
great  difficulty,  and  rarely  succeeds. 

The  anterior  ends  of  the  tubuli  seminiferi  would  seem  from  the 
observations  of  Lauth  and  Krause,*  to  have  different  modes  of  ter- 
minating, some  end  by  cceca,  others  by  a loop,  and  others  by  anas- 
tomosis with  contiguous  tubes.  These  anastomoses  according  to 
Lauth,  are  most  frequent  towards  the  base  of  the  lobules,  and  occur 
there  about  every  three  inches. 

At  the  other  end  of  the  seminal  tubes,  several  unite  into  one,  to 
form  a vas  rectum,  of  which  there  are  at  least  twenty,  and  with  a 
diameter  larger  than  the  tubuli  seminiferi.  The  vasa  recta  are  a 
line  or  two  long,  they  then  are  reduced  into  from  seven  to  thirteen 
trunks,  forming  what  is  called  the  Rete  Vasculosum  Testis,  which  is 
distinguished  by  the  waving  course  of  its  trunks,  and  by  their  fre- 
quent anastomoses  with  each  other. 

According  to  Lauth,  the  number  of  vasa  efferentia  varies,  in  diffe- 
rent subjects,  from  nine  to  thirty,  and  when  the  entire  length  of  each 
one  is  extended  it  measures  eight  inches  ; of  course,  including  the 
conus  Vasculosus. 

The  Epididymis  is  the  prismatic  arch  which  rests  vertically  on 
the  back  of  the  testicle,  and  adheres  to  it  by  the  reflection  of  the 
tunica  vaginalis.  It  is  enlarged  at  both  ends,  the  upper  of  which, 
being  formed  by  the  Coni  Vasculosi  is  called  the  Globus  Major,  and 
the  lower  enlargement  is  the  Globus  Minor.  It  is  made  of  a single 
convoluted  tube,  of  the  fourth  of  a line  in  diameter.  After  this  tube 
has  got  to  the  lower  end  of  the  globus  minor  it  becomes  less  con- 
voluted, enlarges,  turns  upwards  on  the  inner  side  of  the  epididymis, 
and  obtains  the  name  of  Vas  Deferens,  which  before  it  reaches  the 
top  of  the  epididymis  has  become  perfectly  straight,  or  almost  so. 

* Muller,  loc.  cit.  p.  499. 


120 


ORGANS  OF  GENERATION. 


The  average  length  of  the  canal  of  the  Epididymis  is  about  twenty- 
one  feet,  and  the  coni  vasculosi  discharge  into  it  at  intervals  of  three 
inches  and  a-quarter.* 

There  is  a blind  duct,  ( Vasculum  Aberrans ) which  begins  at  the 
top  of  the  epididymis  and  terminates  below ; the  base  of  it  is  up- 
wards, and  the  other  end  discharges  into  the  lower  end  of  the  ca- 
nal of  the  epididymis,  where  the  latter  makes  its  turn  into  the  vas 
deferens.  Its  length  varies  from  one  and  a half  to  fourteen  inches. 
Sometimes  there  are  several.  The  use  is  unknown. 

The  tubuli  seminiferi  form  a system  of  closed  tubes,  with  the  ex- 
ception of  the  posterior  end,  which  discharges  into  the  Rete  Testis. 
Their  diameter  being  about  fifteen  times  greater  than  that  of  the 
arteries  ramifying  upon  them,  the  conclusion  is  drawn  that  their 
whole  internal  surface  executes  the  seminiferous  secretion. 


Of  the  Spermatic  Chord. 

The  Spermatic  Chord  is  a fasciculus  of  about  half  an  inch  in  dia- 
meter, which  may  be  felt  very  readily  through  the  skin  of  the  scro- 
tum, passing  from  the  upper  end  of  the  testicle  to  the  external  ab- 
dominal ring.  It  is  formed  by  the  Vas  Deferens ; the  Spermatic 
Artery  and  Veins  ; the  Lymphatics  of  the  Testicle ; and  the  Nerves  ; 
all  being  covered  in  by  the  Tunica  Vaginalis  Communis,  and  by  the 
Cremaster  Muscle. 

The  Cremaster  Muscle , also  called  the  tunica  elythroides,f  being 
derived  from  the  internal  oblique  and  the  transverse  muscle  of  the 
abdomen,^:  forms  a very  complete  envelope  to  the  chord  from  the 
abdominal  ring  to  the  testicle.  But  when  it  reaches  the  latter  its 
fibres  spread  out  and  become  indistinct  upon  the  tunica  vaginalis 
communis,  as  they  there  consist  in  small,  pale,  scattered  fasciculi ; 
many  of  which  terminate  insensibly,  while  others  form  on  the  front 
of  the  tunica  vaginalis  loops,  having  their  convexities  downwards. 
This  muscle  draws  the  testicle  upwards,  an  action  very  different 
from  the  corrugation  of  the  scrotum. 

The  Vas  Deferens , or  the  proper  excretory  duct  of  the  testicle,  is 
a white  tube  of  about  a line  and  a half  in  diameter,  and  has  a car- 

# Lauth,  see  Muller.  f Em/7$5v,  a sheath,  f See  Abdominal  Muscles 


THE  TESTICLES. 


121 


tilaginous  feel.  Its  parietes  are  thick,  as  its  cavity  will  not  receive 
a body  larger  than  a bristle,  without  being  put  upon  the  stretch.  It 
traverses  a long  space,  and  in  doing  so,  first  passes  at  the  back  of 
the  chord  from  its  commencement  to  the  internal  abdominal  ring: 
having  reached  the  latter,  it  then  abandons  the  spermatic  artery  and 
vein,  and  dipping  into  the  pelvis,  by  the  side  of  the  bladder,  goes 
between  the  lower  fundus  of  the  latter  and  the  ureter.  It  then  con- 
verges towards  its  fellow,  along  the  under  extremity  of  the  bladder, 
at  the  inner  margin  of  the  vesicula  seminalis  of  the  same  side,  and 
finally  terminates  in  the  urethra  near  the  neck  of  the  bladder,  by 
forming  the  Ductus  Ejaculatorius  with  the  assistance  of  the  duct  of 
the  adjoining  vesicula  seminalis.  About  two  and  a half  inches  from 
its  termination,  it  enlarges  and  becomes  somewhat  tortuous. 

This  duct  consists  of  two  coats  : the  external  one  is  hard,  compact, 
and  occasionally  fibres  are  seen  in  it ; but  its  structure  is  not  very 
evident,  and  is  peculiar.  The  internal  is  a mucous  membrane. 

For  the  description  of  the  remaining  portions  of  the  chord,  see 
Spermatic  Artery,  Vein,  Lymphatics,  and  Plexus  of  Nerves. 

The  Testicles  undergo  a remarkable  change  in  their  position, 
from  the  earliest  development  of  their  rudiments  to  the  perfect  foetal 
state.  They  are  not  formed  in  the  scrotum,  but  in  the  abdomen  just 
below  the  kidneys ; from  which  position  they  are  gradually  trans- 
ferred. About  the  middle  of  the  third  month  of  gestation  they  are 
two  lines  long,  and  placed  behind  the  peritoneum,  to  which  they 
loosely  adhere.  The  vas  deferens  then,  instead  of  rising  up  on  the 
side  of  the  epididymis,  goes  straight  down  into  the  pelvis.  At  this 
period  may  be  seen  the  gubernaculum  testis,  discovered  by  J. 
Hunter,*  which  becomes  more  distinct  in  a few  wreeks  afterwards, 
and  assumes  a triangular  appearance.  This  gubernaculum  has  the 
office  of  drawing  the  testicle  down  into  the  scrotum  ; its  point  com- 
mences in  the  upper  part  of  the  latter,  somewhat  below  the  external 
abdominal  ring;  it  passes  through  the  abdominal  canal,  ascends 
upon  the  iliacus  interims  muscle,  and  is  attached  by  its  base  to  the 
inferior  end  of  the  testicle.  In  front  of  the  gubernaculum,  a pro- 
cess, or  small  pouch  of  peritoneum,  passes  through  the  abdominal 
canal  to  the  upper  part  of  the  scrotum.  By  the  contraction  of  the 
gubernaculum,  the  testicle  is  brought,  about  the  seventh  or  eighth 


* Med.  Comment.  Lond.  1777. 


122 


ORGANS  OF  GENERATION. 


month,  into  the  scrotum,  by  sliding  down  behind  the  pouch.  The 
lower  end  of  the  pouch,  at  which  the  testicle  is  finally  arrested,  be- 
comes the  tunica  vaginalis  testis. 

As  soon  as  the  testicle  has  reached  the  scrotum,  the  neck  of  the 
pouch  has  a tendency  to  close  and  to  become  obliterated,  which  is 
commonly  accomplished  at  the  period  of  birth ; yet  it  sometimes 
remains  open  for  a longer  time  and  becomes  the  occasion  of  con- 
genital hernia.  Very  generally  at  birth,  the  orifice  of  the  pouch  will 
receive  the  end  of  a probe  to  the  depth  of  a line  or  two  ; but  all 
below  is  perfectly  closed,  and  has  its  structure  so  condensed  and 
altered,  that  no  one,  from  a view  of  it  alone,  would  suppose  that 
the  cavity  of  the  tunica  vaginalis  had  ever  communicated  with  that 
of  the  peritoneum.* 


SECT.  IV. — OF  THE  MUSCLES  AND  FASCIJE  OF  THE 
PERINEUM,  t 

Perineal  Fascia . 

The  Perineal  Fascia  is  placed  just  beneath  the  skin  of  the  peri- 
neum, and  covers  the  muscles.  It  is  spread  over  nearly  all  the 
space  between  the  anus  and  the  posterior  margin  of  the  scrotum, 
and  between  the  rami  of  the  pubes  and  the  ischia  on  each  side  : it 
is  very  firmly  fixed  to  these  bones,  and  is  gradually  blended  with 
the  cellular  substance  of  the  posterior  part  of  the  scrotum.  This 
fascia  is  rather  thin,  but,  in  case  of  a rupture  of  the  posterior  part  of 
the  urethra,  prevents  the  urine  from  showing  itself  in  the  perineum, 
and  drives  it  into  the  cellular  structure  of  the  scrotum.  In  abscesses 
of  the  perineum,  it  also  prevents  the  fluctuation  from  being  very 
evident. 

* The  explanations  and  anatomy  of  this  process  have  been  treated  at  large 
in  the  following-  works  : 

Girardi,  Tabul.  II.  adj.  Septemd.  Tab.  Santorini. 

J.  Hunter,  Observations  on  certain  parts  of  the  Animal  Economy.  W. 
Hunter,  Med.  Commentaries. 

Edwardi  Standifort,  Opusc.  Anat. 

Wrisberg.  Comment.  Medic.  Physiolog.,  &e. 

f Anat.  Atlas,  Figs.  384,  385, 


MUSCLES  AND  FASCIiE  OF  THE  PERINEUM. 


123 


The  Musculus  Erector  Penis. 

It  is  so  situated,  as  to  cover  the  whole  of  the  crus  of  the  penis 
which  is  not  in  contact  with  the  bony  margin  of  the  pelvis.  It 
arises,  therefore,  tendinous  and  fleshy,  from  the  anterior  part  of  the 
tuber  ischii;  its  fleshy  fibres  adhere  to  the  internal  and  external  mar- 
gins of  the  ramus  of  the  ischium,  and  of  the  pubes,  and  proceed 
upwards:  just  before  the  union  of  the  crura  of  the  penis,  they  end 
in  a flat  tendon  which  is  lost  on  the  side  of  the  corpus  cavernosum 
of  the  penis.* 

Its  use  is  not  well  understood. 


The  Musculus  Accelerator  Urince, 

Lies  on  the  bulb  and  back  part  of  the  corpus  spongiosum  urethrae  ; 
it  is  a thin  muscle,  consisting  of  oblique  fibres. 

It  arises  by  a pointed  production  from  the  side  of  the  body  of  the 
penis  ; its  origin  is  continued  obliquely  across  the  inferior  surface  of 
the  crus  penis,  where  the  latter  begins  to  form  the  body  of  the  penis. 
It  arises,  also,  for  an  inch  from  the  inner  side  of  the  ramus  of  the 
pubes,  between  the  crus  penis  and  the  triangular  ligament  of  the 
urethra.  The  muscles  of  the  opposite  sides  are  inserted  into  one 
another  by  a white  line,  which  marks  the  middle  of  the  bulb  of  the 
urethra  ; and  by  a point,  into  the  anterior  extremity  of  the  sphincter 
ani,  where  they  are  joined  by  the  transversi  perinei. 

V 

In  order  to  see  the  origin  of  these  muscles  very  distinctly,  sepa- 
rate them  from  each  other  in  the  middle  line,  and  dissect  them 
from  the  corpus  spongiosum.  Cut  transversely  through  the  corpus 
spongiosum  about  three  inches  before  the  triangular  ligament,  and 
dissect  it  clearly  from  the  corpus  cavernosum,  turning  it  down- 
wards so  that  it  may  hang  by  the  membranous  part  of  the  urethra. 
By  putting  the  two  acceleratores  on  the  stretch,  it  will  be  seen  that 
besides  the  origins  mentioned,  they  arise,  also,  from  each  other  by 
a tendinous  membrane  that  is  interposed  between  the  corpus  spon- 
giosum and  cavernosum  ; so  that  they  literally  surround  the  back 

* The  late  Dr.  Lawrence  informed  me  that  he  had  frequently  found  mus- 
cular fibres  between  the  bone  and  the  crus  penis. 


124 


ORGANS  OF  GENERATION. 


part  of  the  urethra,  constituting  a complete  sphincter  muscle  for 
it.  This  account  of  the  accelerator  urinse  being  peculiar  to  my- 
self, is  adopted  from  a strong  analogy  between  it  and  the  sphincter 
vaginae. 

The  two  muscles  are  considered  by  M.  Chaussier  as  forming  but 
one : in  that  case  its  origin  will  be  reversed,  and  commence  in  the 
middle  line  of  the  perineum  instead  of  terminating  there.  As  this 
muscle,  and  the  erector  penis,  touch  by  their  contiguous  faces,  it  is 
difficult  to  get  into  the  membranous  part  of  the  urethra  in  lith- 
otomy without  cutting  through  the  muscular  fibres  of  one  or  the 
other. 

It  propels  the  urine  and  semen  forward. 

The  Musculus  Transversalis  Perinei, 

As  its  name  implies,  passes  directly  across  the  perineum  ; it  arises 
from  the  inner  side  of  the  ischium,  just  at  the  origin  of  the  erec- 
tor penis,  and  is  inserted  where  the  sphincter  ani  and  acceleratores 
urinae  join. 

I have  observed  that  when  the  lower  part  of  the  accelerator  was 
extended  much  below  its  usual  line,  and  strongly  developed,  that 
the  transversalis  was  very  irregular  in  its  origin  and  course ; consist- 
ing frequently  of  a few  fibres  which  did  not  deserve  the  name  of  a 
distinct  muscle,  and  lying  almost  unappropriated  in  the  adipose 
matter  of  the  part. 

Occasionally,  a fasciculus  of  muscular  fibres  exists,  called,  by 
Albinus,  Transversus  Perinei  Alter,  which  arises  in  front  of  the 
transversalis : it  seems  generally  to  be  a loose  fasciculus  of  the  ac- 
celerator urinse  muscle,  and  is  inserted  into  the  perineal  junction 
just  behind  it. 

The  use  of  these  muscles  seems  to  be  to  contribute  to  fix  the  bulb 
of  the  urethra. 


The  Musculus  Sphincter  Ani , 

Consists  in  a plane  an  inch  thick,  of  elliptical  fibres  immediately 
beneath  the  skin  of  the  anus,  and  which  surrounds  the  latter  in  order 


MUSCLES  AND  FASCIiE  OF  THE  PERINEUM. 


125 


to  keep  it  closed.  The  long  diameter  of  the  ellipsis  is  extended 
from  the  coccyx  towards  the  symphysis  pubes,  and  has  its  angles 
very  much  elongated  ; the  anterior  may  be  traced  terminating  insen- 
sibly in  the  posterior  face  of  the  scrotum.  It  has  two  fixed  points, 
the  last  bone  of  the  os  coccygis  behind,  and  the  perineal  union  of  the 
other  muscles  in  front ; its  lateral  diameter  occupies  about  one-half 
of  the  space  between  the  tuberosities  of  the  ischia,  and  it  is  in  the 
middle  of  this  space.  This  muscle,  besides  the  fixed  points  men- 
tioned, has  at  its  anterior  and  posterior  ends,  many  fibres  ending 
simply  in  the  subcutaneous  cellular  substance,  and  which  are  much 
more  superficial  than  the  fixed  points. 

Besides  closing  the  orifice  of  the  rectum  it  will  draw  the  bulb 
of  the  urethra  backwards,  or  the  point  of  the  os  coccygis  for- 
wards. 


The  Musculus  Coccygeus , 

Belongs  to  the  interior  of  the  pelvis.  It  arises  by  a small,  ten- 
dinous and  fleshy  beginning,  from  the  spine  of  the  ischium,  and 
lying  on  the  anterior  face  of  the  anterior  sacro-sciatic  ligament,  it  is 
inserted  into  the  side  of  the  last  bone  of  the  sacrum,  and  of  all  those 
of  the  os  coccygis. 

It  draws  the  os  coccygis  forwards. 

It  frequently  happens  that  there  is  on  each  side  a small  fasciculus 
of  muscle  arising  from  the  inferior  bone  of  the  sacrum  in  front,  and 
inserted  into  the  bones  of  the  coccyx  ; it  is  called  Sacro-Coccygeus. 

. A large  quantity  of  adipose  and  cellular  matter  exists  on  the  side 
of  the  rectum,  between  it  and  the  parietes  of  the  pelvis,  concealing 
the  perineal  surface  of  the  levatores  ani  muscles. 


The  Musculus  Levator  Ani , 

Arises,  fleshy,  from  the  back  of  the  pubes  near  its  symphysis,  and 
from  near  the  superior  margin  of  the  foramen  thyroideum  above  the 
obturator  interims  muscle.  It  also  arises  from  the  aponeurosis  pelvica, 
where  this  membrane  is  extended  as  a thickened  semi-lunar  chord 
from  the  superior  margin  of  the  thyroid  foramen  towards  the  spinous 
process  of  the  os  ischium.  This  second  part  of  the  origin  of  the  le- 
Vol.  II. — 12 


126 


ORGANS  OF  GENERATION. 


vator  ani  is  defectively  described  in  most  books  on  anatomy.  It  is 
then  seen  to  cross  obliquely,  as  far  as  the  spine  of  the  ischium,  that 
portion  of  the  obturator  internus  which  arises  from  the  plane  of  the 
ischium. 

From  this  extensive  origin  the  fibres  converge  and  descend  back- 
wards, and  have  three  distinct  places  of  insertion;  the  posterior 
fibres  are  inserted  into  the  last  two  bones  of  the  os  coccygis ; the 
middle,  and  by  far  the  greater  number,  are  inserted  into  the  semi- 
circumference of  the  rectum  between  its  longitudinal  fibres  and  the 
circular  fibres  of  the  sphincter  ani ; and,  finally,  the  most  anterior 
fibres  pass  obliquely  downwards  and  backwards  on  the  side  of  the 
vesical  end  of  the  membranous  part  of  the  urethra,  and  on  the  side 
of  the  prostate  gland,  and  are  inserted  into  the  common  place  of 
junction  of  the  perineal  muscles. 

The  fore  part  of  this  muscle  is  by  some  of  the  English  anatomists, 
called  the  Compressor  Urethrae.* 


The  Triangular  Ligament  of  the  Urethra , 

Is  a membrane  which  fills  up  the  space  below  the  symphysis  of 
the  pubes,  and  answers  there  as  a septum  between  the  perineum  and 
the  pelvis  : when  closely  examined,  it  is  seen  to  connect  itself  to  the 
internal  edges  of  the  rami  of  the  pubes  and  ischia  on  the  inner  pos- 
terior sides  of  the  crura  penis  as  far  down  as  the  beginning  of  the 
latter.  At  its  lower  edge  its  ligamentous  character  is  not  so  well 
defined.  On  its  anterior  surface  is  the  bulb  of  the  urethra,  and  just 
at  the  extremity  of  the  latter,  enclosed  by  the  ligament,  and  adhering 
to  it,  are  Couper’s  Glands.  In  contact  with  it  behind,  and  ad- 
hering, is  the  prostate  gland,  covered  by  its  fibrous  capsule,  which 
is  a continuation  of  the  pelvic  aponeurosis  over  it.  A perforation 
exists  in  it,  through  which  passes  the  membranous  part  of  the  ure- 
thra. This  opening  is  not  very  apparent,  in  consequence  of  its 
edges  being  continued  a little  distance  on  the  canal ; but  by  de- 
taching them  the  whole  becomes  well  defined. 

The  relative  situation  of  the  bulb  and  of  the  membranous  part  of 
the  urethra  is  such,  that  the  former  goes  towards  the  anus,  while  the 
latter  passes  upwards  towards  the  neck  of  the  bladder ; they  conse- 
quently, form  a considerable  angle  with  each  other.  The  mem- 


* Wilson’s  Anatomy,  p.  198. 


MUSCLES  AND  FASCIiE  OF  THE  PERINEUM.  127 

branous  part  of  the  urethra  is  much  the  deepest,  the  recollection  of 
which,  is  all-important  in  lithotomy,  as  it  teaches  us  to  avoid  the 
one,  and  to  cut  into  the  other.  It  may  also  be  observed,  that  the 
hole  in  the  triangular  ligament  is  an  inch  below  the  symphysis  pubis. 

By  removing  the  upper  corner  of  the  triangular  ligament,  we  are 
made  acquainted  with  another  just  behind  it,  which  is  totally  distinct. 
This  ligament  is  half  an  inch  broad,  is  thick  and  strong,  particularly 
at  its  lower  edge,  and  is  very  firmly  attached  laterally  to  each  of  the 
ossa  pubis,  just  below  the  symphysis  : it  is  a continuation  of  the  liga- 
mentous union  of  the  symphysis  pubis.  Mr.  Colies  calls  it  pubic 
ligament  wTith  great  propriety.  I would  suggest,  as  somewhat  more 
expressive,  the  term  Inter-Pubic  Ligament  ;*  as  it  serves  to  distin- 
guish it  from  another  called  Pubic,  which  is  above  the  pubes,  and 
described  in  the  account  of  the  recti  abdominis  muscles.  The 
breadth  of  this  having  been  stated  at  half  an  inch,  it  is  obvious  that 
the  hole  in  the  triangular  ligament  is  half  an  inch  below  its  lower 
edge. 

Pelvic  Fascia. 

The  Pelvic  Fascia  ( Aponeurosis  Pelvica ) connects  the  bladder  to 
the  sides  of  the  pelvis.  “ This  fascia  descends  from  the  ileo-pecti- 
neal  line  to  about  midway  in  the  depth  of  the  pelvis ; here  it  is  re- 
flected from  the  surface  of  the  muscle,  (the  Levator  Ani ,)  and  applies 
itself  to  the  prostate  gland  and  bladder  on  the  body  of  which  it  is 
ultimately  lost.  At  the  angle  of  its  reflection,  this  fascia  appears  par- 
ticularly strong  and  white,  but  becomes  more  weak  and  thin  as  it 
lines  the  muscle  and  covers  the  bladder.  In  tracing  this  membrane 
it  will  be  seen  that  from  the  pubes  just  below  the  symphysis,  a point- 
ed production  of  it,  constituting  its  anterior  margin,  is  fixed  into 
the  side  of  the  neck  of  the  bladder.  This  pointed  production  on 
each  side  is  called,  by  most  anatomists,  the  anterior  ligaments  of  the 
bladder.  Between  them,  just  beneath  the  symphysis  of  the  pubes, 
a pouch  large  enough  to  receive  the  end  of  the  finger,  is  formed  by 
the  union  of  the  fasciae  of  the  two  sides : this  pouch  connects  the 
middle  anterior  part  of  the  neck  of  the  bladder  to  the  lower  margin 
of  the  symphysis  pubis. ”f 

This  fascia  adheres  closely  to  the  periosteum  of  the  pubes,  between 
the  upper  margin  of  the  thyroid  foramen  and  the  crista  of  the  pubes ; 


* See  Symphysis  Pubis. 


f Codes’  Surgical  Anatomy. 


128 


FEMALE  ORGANS  OF  GENERATION. 


about  the  middle  third  of  the  linea  innominata  it  is  obviously  a con- 
tinuous membrane  with  the  iliac  fascia  which  covers  the  iliacus  in- 
terims muscle ; but  behind  this,  again,  it  arises  from  the  remaining 
third  of  the  linea  innominata. 

The  portion  of  this  fascia  which  Mr.  Colies  speaks  of  as  parti- 
cularly strong  and  white,  forms  a bow,,  the  concavity  of  which  looks 
upwards,  one  end  of  the  bow  being  fastened  to  the  pubes  above  the 
foramen  thyroideum,  and  the  other  end  to  the  ischium  above  its 
spine.  The  perineal  surface  of  this  bow  is  an  important  point  of  the 
origin  of  the  levator  ani.  Above  the  bow  this  fascia  is  very  thin,  for 
the  fibres  of  the  obturator  interims  can  be  readily  seen  through  it. 

At  the  bow  the  fascia  divides  into  two  laminae;  one  pursuing  its 
course  to  the  bladder  and  rectum,  the  other  covers  the  lower  part 
of  the  obturator  internus  muscle,  and  thereby  constitutes  the  obtu- 
rator fascia.  The  levator  ani  is  interposed  between  these  two  laminae. 
The  aponeurosis  pelvica  also  forms  a bow  or  semi-lunar  edge  in  front 
of  the  sacral  nerves.  The  triangular  ligament  and  this  fascia  are  so 
identified  in  forming  the  capsule  of  the  prostate,  that  the  capsule  in 
description,  may  be  referred  either  to  the  one  or  the  other,  or  to  both, 
according  to  the  fancy  of  the  describer. 


CHAPTER  II. 

Of  the  Organs  of  Generation  in  the  Female.* 

The  Copulative  Organs  in  the  female  are,  the  Vulva  and  the 
Vagina;  the  Generative  are  the  Uterus  and  the  Ovaria. 

SECT.  I. — OF  THE  VULVA. 

The  term  Vulva  is  applied  to  the  most  superficial  of  the  copulative 
organs,  and  consist  in  the  Mons  Veneris,  the  Labia  Externa,  the 
Labia  Interna,  the  Clitoris,  the  Vestibulum,  the  Orificium  Urethrae, 
the  Fourchette,  and  the  Fossa  Navicularis. 


Anat.  Atlas,  Fig.  39G  to  4Q3,  inclusive. 


THE  VULVA. 


129 


The  Mons  Veneris  is  the  protuberance  on  the  fore  part  of  the 
pubes.  Its  size  varies  considerably,  according  to  the  state  of  obesity 
of  the  subject,  in  consequence  of  its  being  formed  by  a deposite  of 
fat  between  the  skin  and  the  bone  : in  corpulent  women  it  is  very 
large  and  prominent,  whereas,  in  such  as  are  much  emaciated,  it 
simply  describes  the  outline  of  the  bones.  The  skin,  there,  is  abun- 
dantly furnished  with  its  peculiar  glands,  seated  in  the  cellular  texture 
beneath  it,  and  about  the  size  and  shape  of  millet  seed.  At  the  age 
of  puberty  a growth  of  hair  takes  place  upon  it,  which  is  not  so  long 
as  the  correspondent  growth  upon  men,  and  is  not  so  much  disposed 
to  spread  itself  over  the  lower  part  of  the  abdomen  as  life  advances. 
In  women  who  have  abused  coition,  it  is  said  that  these  hairs  become 
much  curled. 

The  Labia  Externa  are  a continuation  of  the  mons  veneris  down- 
wards in  the  form  of  an  oblong  eminence  on  either  side.  Their 
elevation  is  produced  in  the  same  way  by  a deposite  of  fat  beneath 
the  skin.  They  are  somewhat  broader  and  more  prominent  above 
than  below.  On  the  side  which  is  next  to  the  thigh,  the  integu- 
ment is  common  skin,  sparingly  covered  with  hair;  but  on  the  other 
face  it  is  a mucous  membrane,  being  a continuation  of  that  of  the 
vagina.  The  skin  here,  as  well  as  at  the  commencement  of  every 
mucous  membrane,  is  insensibly  changed  into  the  latter.  They 
have  many  sebaceous  and  perspiratory  glands  externally,  and  mu- 
cous glands  internally,  upon  them. 

Much  cellular  membrane,  like  that  of  the  scrotum,  is  found  in 
their  interior  structure;  whereby  they  enjoy  great  extensibility  in 
order  to  favour  the  dilatation  of  the  parts  in  parturition.  The  rima 
which  exists  between  them  is  the  Fissura  Vulvee  of  authors,  and  is 
about  twice  the  length  of  the  orifice  of  the  vagina;  this  arrangement 
of  it  gives  increased  facility  to  the  expulsion  of  the  foetus. 

The  Fourchette  or  Frenulum  Vulvse,  is  situated  at  the  posterior 
commissure  of  the  labia  externa,  and  is  a thin,  narrow  transverse 
duplicature  of  skin ; which,  owing  to  its  weakness,  is  most  fre- 
quently ruptured  at  the  first  act  of  parturition,  and  then  disappears. 

The  Clitoris  bears,  in  some  respects,  a resemblance  to  the  penis 
of  the  male,  but  is  by  no  means  so  large.  It  is  situated  immediately 
below  the  symphysis  pubis,  and  consists  in  a cylindrical  body  of 
three  or  four  lines  in  diameter,  with  two  crura.  The  body  is  an 

12* 


1-30 


FEMALE  ORGANS  OF  GENERATION. 


inch  long;  the  crura  are  likewise  of  the  same  length,  and  arising 
from  the  internal  face  of  the  crura  of  the  pubes,  unite  beneath  the 
symphysis  so  as  to  form  the  body.  The  body  is  not  straight,  but 
has  the  anterior  half  bent  downwards  and  forwards.  The  exterior 
covering,  or  capsule  of  the  clitoris,  in  its  texture,  resembles  the 
elastic  ligamentous  membrane  of  the  corpus  cavernosum  penis  ; and 
is,  moreover,  filled  within  by  a similar  cavernous  or  cellular  struc- 
ture, which  is  divided  into  two  equal  parts  by  a septum  pectiniforme, 
and  is  susceptible  of  distention  during  sexual  excitement.  The 
clitoris  is  supplied  also  with  blood  vessels  and  nerves  like  the  penis, 
and  is  held  up  to  the  under  part  of  the  symphysis  pubis  by  a sus- 
pensory ligament. 

The  anterior  extremity  of  the  body  of  the  clitoris  is  found  in  the 
ritna  or  fissura  vulvae,  about  an  inch  below  the  upper  commissure 
of  the  labia  externa.  It  projects  somewhat,  and  bears  a general 
resemblance  in  shape  with  the  end  of  the  penis,  whence  its  name 
of  glans  clitoridis;  but  it  has  not  the  same  organization,  excepting 
the  delicacy,  the  extreme  sensibility,  and  the  vascularity  of  the  skin 
which  covers  it.  The  clitoris  has  no  corpus  spongiosum,  neither  is 
it  concerned,  like  the  penis,  in  conveying  the  urine  from  the  blad- 
der. Its  glans  is  covered  by  a doubling  of  skin  called  the  prepuce, 
and  is  likewise  furnished  with  the  gland  ulae  Tysoni,  from  which  is 
discharged  a smegna,  or  sebaceous  fluid,  as  in  the  male.  The  pre- 
puce does  not  furnish  a regular  well  defined  fraenum. 

The  Erector  Clitoridis  muscle  corresponds  with  the  erector  penis. 
It  arises  from  the  ascending  ramus  of  the  ischium,  and,  covering 
the  inferior  face  of  the  crus  clitoridis,  runs  as  far  forwards  as  the 
commencement  of  the  body. 

The  Labia  Interna,  or  Nymphae,  are  two  duplicatures  of  the 
mucous  membrane  of  the  vulva,  which  pass  down,  one  on  each 
side,  from  the  clitoris.  The  prepuce  of  the  latter  terminates,  on 
either  side,  in  the  labia;  while  the  latter  are  continued  upwards, 
by  a narrow  process,  to  the  under  surface  of  the  glans  clitoridis. 
They  arise  all  along  their  base,  from  the  internal  sides  of  the  labia 
externa,  or  majora;  and  being  wider  in  the  middle  than  elsewhere, 
they  terminate  insensibly  about  half-way  down  the  orifice  of  the 
vagina.  Between  the  laminae  of  each  one  is  placed  a vascular 
cellular  substance,  susceptible  of  distention  and  of  partial  erection 
during  sexual  excitement.  In  young  subjects,  their  vascularity 


THE  VULVA. 


131 


i 

/ 

communicates  a vermilion  tinge,  which  is  lost  and  becomes  brown- 
ish in  the  progress  of  life.  As  they  are  effaced  during  parturition, 
their  chief  use  seems  to  be  as  a provision  for  the  great  distention  of 
the  vulva,  which  then  occurs. 

The  labia  interna  are  about  half  an  inch  broad  in  the  natural  state, 
and  do  not  project  obviously  beyond  the  labia  externa,  except  in 
cases  of  extreme  emaciation,  where  the  prominence  of  the  latter  has 
been  destroyed  by  a removal  of  its  fat.  They  are,  however,  very 
subject,  as  the  individual  becomes  old,  to  a pointed  elongation,  in- 
creasing their  breadth  to  an  inch,  or  an  inch  and  a-half;  and  to  be- 
come thickened  and  indurated.  A tribe  of  Hottentots,  the  Boschis- 
mans,  living  near  the  Cape  of  Good  Hope,  are  uniformly  subject  to 
this  enlargement;  which,  for  a long  time,  was  represented,  by 
travellers,  as  an  organ  superadded  to  what  is  common  in  the  human 
species. 

The  Vestibulum  is  a depression  of  twelve  or  fifteen  lines  long 
between  the  labia  interna ; it  is  bounded  above  by  the  clitoris,  and 
below  by  the  orifice  of  the  vagina.  It  is  abundantly  furnished  with 
mucous  lacunae. 

The  Urethra  of  the  female  has  its  external  orifice  ( Orificium 
Urethra ) in  the  inferior  part  of  the  vestibulum,  about  one  inch 
below  the  glans  clitoridis,  and  is  generally  marked  by  a slight 
rising,  which  is  easily  distinguished  by  the  sensation  of  touch 
alone ; its  margin  is  often  bounded  by  a little  caruncle  on  each 
side.*  The  urethra  itself  is  an  inch  long,  larger  and  much  more 
dilatable  than  that  of  the  male,  its  course  is  obliquely  downwards 
and  forwards  from  the  neck  of  the  bladder;  passing  under  the 
symphysis  of  the  pubes,  and  being  slightly  curved  from  that  cause. 
It  consists  of  two  membranes,  a lining  and  an  external  one.  The 
lining  membrane  is  a continuation  of  that  of  the  bladder;  it  is 
thrown  into  several  longitudinal  folds,  and  has  many  mucous  folli- 
cles in  it.  The  external  coat  of  the  urethra  consists  of  condensed 
laminated  cellular  membrane,  having  a strong  affinity  with  mus- 
cular fibre:  the  principal  direction  of  the  fibres  is  transverse,  form-- 

* Professor  Pancoast  considers  the  urethra  of  the  young  female  to  have  its 
orifice  on  a level  with  the  anterior  face  of  the  Symph.  Pubis,  whereas,  in  such  as 
have  borne  many  children  it  is  behind  the  pubes. . Yvistars  AnaL.  vol.  ii.  p._ 
182.  Phil.  183,9.; 


132 


FEMALE  ORGANS  OF  GENERATION. 


ing  a cylindrical  body  of  half  an  inch  in  its  transverse  diameter, 
and  which  has  given  the  idea  of  the  existence  of  a prostate  gland 
in  the  female:  the  lower  and  lateral  surfaces  of  this  cylinder  are 
in  contact  with  the  vagina,  forming  a protuberance  into  its  cavity; 
and  the  upper  surface  is  firmly  connected  to  the  triangular  liga- 
ment of  the  pubes.  Immediately  behind  the  neck  of  the  bladder, 
we  find  the  vesical  triangle  with  its  muscle,  as  in  the  male,  except- 
ing that  the  anterior  angle  of  it  goes  to  the  anterior  end  of  the 
urethra. 

The  Fossa  Navicularis  is  that  portion  of  the  rima  vulvse  which 
is  below  the  vestibulum,  and  anterior  to  the  orifice  of  the  vagina. 


SECT.  II. — OF  THE  VAGINA. 

The  vagina  is  a thin  membranous  canal  which  leads  from  the 
vulva  to  the  uterus.  It  is  from  four  to  six  inches  in  length,  differ- 
ing according  to  age  and  pregnancy,  and  being  much  shorter  in 
women  who  have  borne  children  than  in  virgins.  It  is  placed  be- 
tween the  bladder  in  front,  and  the  rectum  behind,  being  flattened 
by  them  so  as  to  bring  its  anterior  and  posterior  surfaces  into  con- 
tact. Its  anterior  extremity  is  the  smallest  of  the  two;  and  pre- 
sents its  greatest  diameter  vertically,  while  that  of  the  posterior  is 
transverse.  As  it  follows  accurately  the  central  line  of  the  pelvis, 
it  is,  consequently,  curved  with  its  concavity  forwards.  Its  ante- 
rior parietes  are  shorter  than  the  posterior,  both  from  the  smaller 
depth  of  the  pelvis  in  this  direction,  and  from  the  mode  of  con- 
nexion with  the  uterus. 

The  vagina  is  formed  by  two  tunics;  a fibrous  and  a mucous 
one.  The  first  is  external,  of  a light  red  colour,  highly  elastic, 
and  seems  to  consist  of  condensed  cellular  membrane,  the  fibres 
of  which  are  much  intermixed,  and  pass  in  every  direction.  It  is 
vascular,  and  immediately  adjacent  to  the  large  venous  sinuses  of 
the  pelvis.  The  mucous  membrane  being  a continuation  of  that 
of  the  vulva,  is  at  and  near  its  anterior  orifice  of  a vermillion  tinge; 
while,  posteriorly,  it  is  grayish  and  frequently  spotted,  so  as  to  give 
it  a marbled  appearance:  its  thickness  diminishes  as  it  recedes 
from  the  external  orifice;  and  upon  being  floated  in  water,  many 
mucous  lucunse  are  observable  upon  it. 

The  internal  surface  of  the  vagina  is  commonly  covered  with 


THE  VAGINA. 


133 


the  mucus  which  comes  from  its  lacunae.  On  the  anterior  or 
pubic  portion,  it  is  divided  longitudinally  by  a middle  ridge,  which 
commences  by  a sort  of  tubercle  just  below  the  orifice  of  the 
urethra,  and  proceeds  backwards,  becoming  indistinct  as  it  ap- 
proaches the  uterus.  Transverse  ridges  formed  in  the  same  way 
by  folds  of  the  mucous  membrane,  arise  from  the  sides  of  the  last 
at  its  anterior  portion,  and  give  a roughness  to  that  part  of  the  va- 
gina. The  inferior  side,  or  that  next  to  the  rectum,  has  the  same 
kind  of  arrangement  of  the  mucous  membrane,  but  not  os  distinct.  • 
In  a majority  of  subjects,  the  uterine  half  of  the  vagina  is  perfectly 
smooth,  but  the  rule  does  not  always  hold.  The  internal  membrane 
of  the  vagina  is  covered  by  its  epithelium,  the  scales  or  cells  of 
which  are  detached  and  found  in  the  secretion  of  mucus. 

The  Corpus  Spongiosum  Vaginae  is  an  erectile  tissue,  like  that  of 
the  penis,  and  closely  resembles  in  structure  the  corpus  spongiosum 
urethrae.  It  is  placed  at  the  anterior  end  of  the  vagina,  on  its  outer 
circumference,  just  below  the  clitoris,  and  at  the  base  of  the  labia 
minora  or  interna.  It  is  an  inch  broad,  and  a line  or  two  thick,  ad- 
heres closely  to  the  fibrous  coat  of  the  vagina,  and  extends  around 
the  superior  semicircumference  of  the  orifice,  but  not  around  the  in- 
ferior. It  is  frequently  called  Plexus  Retiformis. 

The  Sphincter  Vaginas  Muscle  surrounds  the  anterior  orifice  of 
the  vagina,  and  covers  the  plexus  retiformis.  It  is  about  an  inch 
and  a quarter  wide,  and  arising  from  the  body  of  the  clitoris  and 
the  crus  of  the  pubes,  behind  the  crus  of  the  clitoris,  passes  back- 
wards and  downwards  to  be  inserted  into  the  dense,  white  sub- 
stance, in  the  centre  of  the  perineum,  common  to  these  muscles, 
the  transversi  perinei  and  the  anterior  point  of  the  sphincter  ani. 
There  is  a strong  analogy  between  it  and  the  accelerator  urinre  of 
the  male. 

The  Transversus  Perinei  of  the  female,  has  the  same  circum- 
stances of  origin  and  insertion  as  in  the  male,  but  is  not  quite  so 
strong. 

On  each  side  of  the  orifice  of  the  vagina,  near  its  middle,  is  fre- 
quently found  a mucous  gland,  the  size  of  a garden  pea : it  corre- 
sponds with  Couper’s  gland  of  the  male  subject. 


134 


FEMALE  ORGANS  OF  GENERATION. 


The  Hymen,*  one  of  the  attributes  of  the  virgin  state,  is  placed 
at  the  anterior  orifice  of  the  vagina  for  the  purpose  of  closing  it,  and 
commonly  remains  until  it  is  ruptured  by  violence.  In  all  cases 
except  where  there  is  an  unnatural  adhesion,  it  leaves  a small  orifice 
for  the  passage  of  mucus  and  of  menstrual  blood.  In  my  own  ob- 
servations, I have  found  it  most  frequently  crescentic,  the  convexity 
of  the  crescent  presenting  downwards,  and  the  horns  upwards  ; but 
in  some  cases  it  is  to  one  side.  Next  in  frequency  to  the  lunated  is 
'die  circular  shape,  where  it  surrounds  completely  the  orifice  and 
leaves  a hole  in  its  own  centre.  There  are  some  other  varieties, 
such  as  its  being  fleshy,  fasciculated,  unequally  divided  into  two 
portions,  and  so  on,  which  are  narrated  by  different  writers.  Being 
simply  a duplicature  of  the  mucous  membrane,  it  is  generally  so  weak 
as  to  be  ruptured  at  the  first  act  of  copulation;  or  even  from  slighter 
causes  during  infancy : but  occasionally,  it  becomes  thickened,  and 
so  strong  as  to  require  division  with  the  knife.  Upon  the  rupture  of 
the  hymen,  its  place  is  indicated  in  subsequent  life  by  from  two  to 
six  small  tubercles,  called  Carunculae  Myrtiformes,  which  are  its 
remains. 

The  peritoneum,  in  descending  from  the  uterus,  anteriorly, 
touches  the  top  of  the  vagina  for  a little  distance,  and  is  then  re- 
flected to  the  bladder,  but  posteriorly,  almost  the  upper  half  of  the 
vagina  has  a peritoneal  coat  before  this  membrane  is  reflected  to  the 
rectum.  The  attachment  of  the  vagina  to  the  bladder  is  strong  and 
close  just  above  the  urethra,  but  its  connexion  with  the  rectum  is  by 
rather  loose  cellular  substance. 


SECT.  m. — OF  THE  UTERUS,  AND  ITS  APPENDAGES. 

The  Uterus,  or  Womb,  is  a compressed  pyriform  body,  the  larger 
end  of  which  stands  upwards,  while  the  lower  is  directed  down- 
wards, and  is  attached  to  the  vagina. f Unimpregnated,  it  is  two 

* J.  G.  Tolber,  Diss.  de  Variet.  Hymen. — Haller,  Icon.  Anat.  Fasc.  i. — 
Albin.  Acad.  Annot.  Lib.  iv. — Santorini,  Septemd.  Tab. 

f This  is  commonly  represented  by  anatomists  in  their  plates  and  descrip- 
tions as  the  position  of  the  womb ; it  is,  however  more  so  in  advanced  preg- 
nancy than  when  empty.  In  my  dissections  generally,  I have  found  the  pos- 
terior face  of  the  womb  downwards,  reposing  upon  the  concavity  of  the  rectum, 
and  the  os  tineas  obliquely  forwards;  this  position  being  probably  produced  by 


UTERUS,  AND  ITS  APPENDAGES. 


135 

and  a half  inches  long,  and  one  and  a half  in  diameter  at  its  widest 
part.  The  posterior  face  is  very  convex,  while  the  anterior  is  al- 
most fiat,  or  very  slightly  convex.  It  is  about  one  inch  in  thick- 
ness. It  is  divided  by  anatomists  into  fundus,  body,  and  neck. 
The  fundus  is  formed  by  its  superior  extremity,  and  comprises  the 
space  between  the  orifices  of  the  Fallopian  tubes  : the  neck  is  the 
lower  cylindrical  portion,  of  about  an  inch  in  length  ; and  the  body 
is  the  part  intermediate  to  the  two.  On  the  exterior  circumference 
of  the  uterus,  there  are  no  marks  or  lines  distinguishing  these  several  * 
portions,  from  each  other. 

The  uterus,  being  destined  to  lodge  the  foetus  from  a short  pe- 
riod after  conception  to  the  moment  of  birth,  has  a cavity  ready 
for  its  reception.  The  shape  of  this  cavity  bears  some  general,  but 
not  a rigid  resemblance  to  that  of  the  organ  itself,  and  it  is  so 
much  flattened  as  to  have  its  anterior  and  posterior  parietes  in  con- 
tact, or  nearly  so.  The  cavity  of  the  body  is  an  equilateral  trian- 
gle of  eight  or  ten  lines  in  diameter ; the  sides  of  the  triangle  are 
bent  inwards  in  parabolic  curves,  in  such  a way  as  to  present  their 
convexities  to  the  cavity  of  the  uterus:  this  of  course,  occasions  an 
apparent  elongation  of  the  angles.  The  inferior  angle  is  continued 
into  the  cavity  of  the  neck,  while  the  two  superior  run  into  their 
respective  Fallopian  tubes.  From  this  arrangement  it  happens  that 
the  parietes  of  the  uterus  are  only  three  lines  thick  on  the  angles 
of  the  triangular  cavity,  while  at  the  middle  they  are  from  four  to 
six  lines.  The  cavity  of  the  neck  has  not  its  anterior  and  poste- 
rior sides  so  near  together  as  those  of  the  body;  and  is  rather  cy- 
lindrical, being  smaller,  however,  at  the  upper  and  lower  ends  than 
in  the  middle.  This  arrangement  gives  to  its  sides  a paraboloid 
curvature  which  presents  its  convexity  outwards,  differing  in  that 
respect  from  the  corresponding  curvature  in  the  cavity  of  the  body. 

The  cavity  of  the  neck  terminates  in  the  vagina  by  an  orifice 

the  superincumbence  of  the  small  intestines,  and,  especially,  when  the  blad- 
der is  empty.  When  the  latter  is  full,  the  peritoneum  is  reflected  from  the 
centre  of  the  uterus  to  the  posterior  face  of  the  bladder,  and  its  traction  has  the 
effect  of  erecting  the  uterus  in  part,  from  its  nearly  horizontal  direction.  In  the 
dissection  of  a female,  April  9,  1838,  aged  eighteen,  who  died  from  an  affec- 
tion of  the  brain,  there  being  every  evidence  of  soundness  in  the  genital  organs, 

1 found  the  rectum  making  a curve  to  the  right  side  of  the  inferior  part 
of  the  sacrum,  and  the  body  of  the  womb,  reposing  in  the  concavity  of  the 
latter. 


136 


FEMALE  ORGANS  OF  GENERATION. 


about  the  size  of  a small  writing-quill,  but  ovoidal,  and  presenting 
its  long  diameter  transversely.  This  orifice  is  the  Os  Tincse,  or 
Orificium  Externum  Uteri ; frequently,  without  apparent  disease,  I 
have  seen  it  conoidal,  with  its  base,  half  an  inch  in  diameter,  pre- 
senting downwards.  The  upper  orifice  whereby  the  cavity  of  the 
neck  communicates  with  that  of  the  body  is  not  subject  to  such 
fluctuations  in  size:  it  is  occasionally  called  Orificium  Internum 
Uteri,  and  is  generally  somewhat  larger  than  a small  writing-quill. 
The  os  tincse  is  bounded  before  and  behind  by  the  lips  of  the  uterus, 
formed  by  the  projection  of  the  neck  into  the  vagina.  For  the 
most  part  the  anterior  lip  is  directly  continuous  with  the  anterior 
side  of  the  vagina:  so  that  its  projection  is  very  inconsiderable, 
and,  indeed,  not  appreciable  to  the  finger:  at  the  same  time,  this  lip 
is  rather  thicker  than  the  posterior.  The  projection  of  the  latter, 
on  the  contrary,  is  always  well  marked,  because  the  vagina,  instead 
of  being  inserted  into  its  ridge,  is  joined  to  the  posterior  surface  of 
its  base. 

The  cavity  of  the  uterus  is  lined  by  a very  thin  mucous  mem- 
brane, a continuation  of  that  of  the  vagina.  This  membrane  is  of 
a light  pink  colour,  which  changes  to  a Vermillion  during  the  pe- 
riod of  menstruation;  it  is  said  to  be  furnished  with  villosities, 
which,  though  seen  with  difficulty  in  the  usual  way,  may  be  ren- 
dered apparent,  by  floating  the  uterus  in  water;  and  it  adheres  so 
closely  to  the  substance  of  the  uterus,  that  it  forms  an  inseparable 
portion  of  it,  which  can  neither  be  dissected  nor  macerated  off’  en- 
tirely, as  in  the  case  of  other  mucous  membranes. 

This  membrane  is  smoothly  laid  upon  the  cavity  of  the  body,  and 
gives  it  a polished  shining  surface.  On  the  cavity  of  the  neck,  it 
is  wrinkled  along  the  anterior  and  the  posterior  parts;  there  being 
a longitudinal  line  running  along  the  centre,  and  on  each  side  of 
this  line  transverse  or  oblique  elevations  or  duplicatures.  This  ar- 
rangement presents  an  arborescent  appearance,  technically  called 
the  arbor  vitae.  In  the  interstices  of  these  duplicatures  there  are 
some  small  mucous  glands  or  lacuna3,  which  as  their  orifices  are 
exposed  to  obliteration  from  inflammation  or  some  other  irritation, 
become  distended  into  small  spherical  sacs  by  the  accumulation  of 
their  habitual  secretion.  Naboth,  from  seeing  them  in  this  state, 
mistook  them  for  eggs,  or  the  rudiments  of  the  foetus,  and  the 
error  has  been  commemorated  by  their  being  called  Ovula  Na- 


THE  VAGINA. 


137 


bothi.  This  membrane  is  covered  by  an  epithelium  which  is  vibra- 
tile  to  the  middle  of  the  neck,  and  afterwards  pavement-like. 

The  uterus  is  covered  completely  by  the  peritoneum;  in  the  re. 
flection  of  the  latter,  from  the  rectum  to  the  bladder,  it  adheres  to 
the  uterus  by  a subjacent  cellular  substance,  which  allows  it  to  be 
dissected  off  without  difficulty.  The  same  duplicature  of  peritoneum 
which  encloses  the  uterus,  is  also  reflected  from  each  of  its  lateral 
margins,  by  their  whole  length  to  the  corresponding  side  of  the  lesser 
pelvis,  and  forms  the  Lateral  or  the  Broad  Ligaments,  ( Ligamenta 
Later  alia,  Lata.)  The  peritoneum  in  passing  from  the  uterus  for- 
wards to  the  bladder,  forms  on  each  side,  a duplicature,  not  very 
distinct,  and  depending,  in  a measure,  upon  the  state  of  the  bladder; 
this  constitutes  the  Anterior  Ligament.  The  same  membrane  in 
passing  from  the  back  of  the  uterus  to  the  rectum,  and  in  covering 
the  posterior  superior  end  of  the  vagina,  also  forms,  on  each  side, 
a duplicature,  denominated  the  Posterior  Ligament;  it  is  always 
better  seen  than  the  anterior.  Muscular  fibres  are  said  to  be  found, 
occasionally,  between  the  laminae  of  these  several  duplicatures,  run- 
ning in  the  direction  of  the  latter;*  they  have  not  been  presented  to 
me  in  such  a way  as  to  arrest  my  attention. 

The  broad  ligaments,  along  with  the  uterus,  form  a transverse 
septum,  passing  from  one  side  of  the  pelvis  to  the  other ; and  con- 
tain, between  their  laminae,  the  arteries  and  the  veins  which  belon°- 
to  the  uterus  and  ovaries. 

Besides  the  duplicatures  of  peritoneum,  the  uterus  is  retained  in 
its  position  by  the  Ligamenta  Rotunda,  one  on  each  side.  These 
round  ligaments  arise  from  the  side  of  the  uterus,  a little  below  the 
insertion  of  the  Fallopian  Tube,  and  going  between  the  laminae  of 
the  broad  ligament,  reach,  finally,  the  internal  abdominal  ring : they 
then  traverse  the  abdominal  canal  and  the  external  ring  after  the 
manner  precisely  of  the  spermatic  chord,  and  terminate  by  several 
fasciculi  in  the  fatty  cellular  matter  of  the  mons  veneris  and  of  the 
labia  majora.  The  round  ligaments  are  rather  smaller  in  the  middle 
than  at  either  extremity ; they  consist  of  a condensed  cellular  or 
fibrous  structure,  and  have  many  blood  vessels  in  them.  It  has 
been  asserted,!  that  they  contain  strongly  marked  muscular  fibres  ; 
some  of  which  come  from  the  uterus,  and  others  from  the  broad 

* J.  F.  Meckel*  vel.  ii.  p.  C05. 

Vol.  II.— 13 


f J.  F.  Meckel,  loc.  cit. 


138 


FEMALE  ORGANS  OF  GENERATION. 


muscles  of  the  abdomen.  No  evidence  of  this  fact  has  as  yet  been 
presented  to  me,  though  I do  not  deny  it;  and,  indeed,  I think  it 
probable,  that  such  fibres  may  be  developed  there  during  gestation. 

The  texture  of  the  uterus  is  very  compact,  and  of  a cartilaginous 
feel ; it  is  composed  of  fibrous  matter,  intermixed  with  a great  many 
blood  vessels.  In  regard  to  its  fibrous  structure,  there  is  no  subject 
in  anatomy  upon  which  opinions  are  more  divided,  or  more  authori- 
tative and  numerous  on  both  sides  of  the  question.  Some  deny  its 
existence  at  any  period,  while  others  admit  it  as  a constant  condi- 
tion : others,  again,  limit  its  duration  only  to  the  period  of  pregnancy. 
Without  dwelling  on  the  value  of  the  several  doctrines,  and  the 
means  and  observations  tending  to  support  them,  it  may  be  suffi- 
cient here  to  mention  that  the  structure  of  the  uterus  takes  on  very 
important  and  strongly  marked  changes,  in  passing  from  the  unim- 
pregnated state  to  that  of  advanced  gestation.  In  the  first  the  fibres 
look  ligamentous  and  pass  in  every  direction,  but  so  as  to  permit 
the  uterus  to  be  lacerated  more  readily  from  the  circumference  to 
ihe  centre  than  in  any  other  course : it,  indeed  manifests  an  indis- 
position to  be  torn  in  a laminated  manner.  The  fibres,  moreover, 
break  off  short,  are  separated  by  the  blood  vessels,  and  seem  1o  con- 
tain, in  their  interstices,  something  like  fibrine. 

In  the  impregnated  state,  on  the  contrary,  the  vessels  being  im- 
mensely increased  in  size,  the  laminated  structure  becomes  very 
evident,  and  submits  readily  to  the  tearing  of  one  layer  from  the 
other : these  laminae  consist  of  fibres,  which  are  principally  parallel 
with  each  other.  The  muscular  nature  of  these  fibres  seems  to  be 
sufficiently  proved,  by  their  powerful  contraction  in  the  expulsion  of 
the  foetus,  and  on  being  irritated  by  the  introduction  of  the  hand. 
They  are,  however,  not  red  like  other  muscles,  but  of  a very  light 
colour  as  those  of  the  bladder  and  intestines ; and  are  collected  into 
fasciculi  of  peculiar  flatness  and  looseness.  The  development  of 
this  muscular  structure  is  not,  always,  limited  to  the  pregnant  state, 
but  is  disposed  to  manifest  itself  on  many  occasions  which  produce 
an  increased  size  in  the  uterus.  This  fact  was  first  exemplified  to 
me  in  a small  scirrhus  of  a virgin  uterus,  presented  by  Dr.  Hugh 
L.  Ilodge,*  and  has  been  still  farther  confirmed  in  a case,  where 
the  scirrhus  was  five  or  six  inches  in  diameter ; also  in  a virgin 
uterus,  very  much  enlarged  from  scirrhus,  presented  by  Professor 

* Now  Professor  of  Obstetrics  in  the  University  of  Pennsylvania.- 


UTERUS,  AND  ITS  APPENDAGES. 


139 


Charles  D.  Meigs.*  A similar  fact  has  been  noticed  by  Lobstein, 
of  Strasburg,  where  the  tumour  was  also  steatomatous. 

The  fibres  of  the  uterus,  examined  near  the  term  of  pregnancy, 
consist  in  two  planes  separated  by  the  large  bloodvessels;  one 
within  and  the  other  without.  These  layers  are  readily  divisible 
into  subordinate  laminae,  intermixed  with  one  another  but  yet  to  a 
considerable  extent  separable.  The  external  layer  is  thicker  than 
the  internal,  and  both  have  an  increased  thickness  at  the  fundus: 
while  they  are  much  diminished,  and  indeed  indistinct,  at  the 
cervix. 

The  fibres  generally  are  either  circular  or  longitudinal,  but  many 
of  them  are  oblique.  The  exterior  surface  of  the  external  plane,  is 
composed  principally  of  longitudinal  fibres,  within  which  are  the 
circular.  The  inner  plane,  on  the  contrary,  has  the  circular  fibres 
external,  and  the  longitudinal  internal.  In  both  planes  the  circular 
fibres  are  more  abundant  at  the  fundus,  and  the  longitudinal  upon 
the  body  of  the  uterus ; but,  generally  speaking,  there  are  collec- 
tively more  longitudinal  than  circular  fibres. 


Of  the  Fallopian  Tubes. 

The  Fallopian  tubes  ( Tubes  Fallopiance ) are  two  membranous 
canals,  one  on  either  side,  fixed  in  the  superior  margin  of  the  broad 
ligament  of  the  uterus.  They  serve  to  conduct  the  rudiments  of 
the  embryo  from  the  ovarium  into  the  uterus.  They  are  about  four 
inches  long,  and  extend  from  the  upper  angle  of  the  uterine  cavity 
to  the  side  of  the  pelvis:  their  outer  extremity  is  loose,  and  hangs 
upon  the  posterior  face  of  the  broad  ligament  over  the  ovarium, 
consequently  inclines  downwards,  thereby  forming  an  angle  with 
the  other  portion. 

At  their  uterine  extremities  the  Fallopian  tubes  are  about  the  size 
of  the  vas  deferens,  resemble  it  strongly,  and  scarcely  admit  a hog’s 
bristle;  but  having  proceeded  about  one-half  of  their  length,  they 
begin  to  enlarge,  and  continue  to  do  so  rapidly  for  an  inch,  until 
they  reach  the  size  of  a writing-quill;  they  then  contract  again 
somewhat,  and  immediately  afterwards  expand  into  a broad  trumpet- 


* Of  the  Jefferson  Med.  College. 


140 


FEMALE  ORGANS  OF  GENERATION. 


shaped  mouth.  The  latter  has  an  oblique  orifice,  the  edge  of  which 
is  extremely  irregular,  by  being  resolved  into  a number  of  ragged 
fringe-like  processes,  of  unequal  size  and  length;  and  which,  as  a 
whole,  are  called  Corpus  Fimbriatum,  or  Morsus  Diaboli.  One  of 
the  longest  of  these  processes  adheres  to  the  external  end  of  the 
ovarium. 

The  Fallopian  tube  is  covered  by  the  peritoneum,  and  consists 
of  two  coats:  the  external  is  fibrous,  and  bears  sufficient  resemblance 
to  the  structure  of  the  uterus  to  be  considered  a continuation  of  it; 
the  internal  is  mucous,  and  is  likewise  a continuation  of  the  corres- 
ponding one  of  the  uterus.  The  external  end  of  the  tube,  which  is 
called  Pavilion  by  the  French  anatomists,  is  flaccid,  thin,  and  gene- 
rally in  a collapsed  state,  as  it  is  formed  solely  by  the  mucous  mem- 
brane, assisted  by  the  peritoneum,  neither  of  which  furnishes  re- 
sistance sufficient  to  keep  it  expanded ; but,  as  many  blood  vessels 
enter  into  its  composition,  their  turgescence,  in  sexual  excitement, 
probably  communicates  a certain  degree  of  erection. 

Mr.  Grainger  has  ascertained  that  the  Fallopian  tube  presents  a 
difference  in  the  structure  of  its  mucous  membrane,  the  part  next 
the  uterus,  not  being  so  vascular  as  the  other  part:  moreover,  the 
latter  presents  a complex  arrangement  in  the  form  of  folds  or  valves 
running  in  a longitudinal  direction  and  plaited.  We  are  left  to 
infer  that  the  difference  is  more  conspicuous  shortly  after  concep- 
tion.* There  is  some  similitude  in  this  arrangement  with  the  ovi- 
ducts of  birds,  one  part  of  which  secretes  the  albumen  of  the  egg, 
and  another  part,  the  shell;  and  it  may  be  in  the  human  subject,  also, 
that  the  two  parts  execute  different  offices  in  the  perfection  of  the 
ovum. 

Of  the  Ovaries . 

The  Ovaries,  ( Ovaria , Testes  Muliebres,)  two  in  number,  one  on 
either  side,  are  situated  on  the  posterior  face  of  the  broad  ligaments 
by  a duplicature  of  which  they  are  surrounded,  and  are  twelve  or 
fifteen  lines  below  the  Fallopian  tubes.  Their  shape  is  that  of  a 
compressed  ovoid,  about  half  the  size  of  the  male  testicle:  their  long 
diameter  is  horizontal ; they  are  suspended  from  the  broad  ligament 
rather  by  the  edge  than  by  the  flat  surface,  so  that  they  project,  and 


* Muller’s  Physiol.,  p.  1563. 


THE  OVARIES. 


141 


are  to  a considerable  degree  pendulous.  Their  distance  from  the 
uterus  varies  from  an  inch  to  an  inch  and  a-half,  and  from  the  in- 
ternal end  of  each  one  there  proceeds  a small  vascular  fibrous  cord, 
the  Ligament  of  the  Ovarium,  which  is  inserted  into  the  uterus, 
somewhat  below  the  origin  of  the  Fallopian  tube. 

From  their  being  the  seat  of  conception,  they  have,  in  the  youth- 
ful and  healthy  female,  a pliancy  and  succulency,  indicative  of  their 
state  of  preparation  for  the  act;  but  in  advanced  life  they  diminish 
much  in  volume  and  become  hard  and  dry.  Their  surface,  origi- 
nally smooth  or  slightly  embossed,  is  subsequently  rendered  uneven, 
by  repeated  acts  of  conception,  leaving  on  it  a number  of  cicatrices 
or  small  stellated  fissures.  They  are  of  a light  pink  colour. 

Within  the  peritoneal  coat  is  another,  the  Tunica  Albuginea,  of 
a strong,  compact,  fibrous  texture,  like  the  same  coat  of  the  testicle, 
and  sending  inwards  many  processes. 

The  structure  of  the  ovarium  is  as  follows : But  few  females,  of 

those  presented  in  our  dissecting  rooms,  have  the  part  in  a state  fit 
for  study,  owing  to  age,  disease,  or  excessive  sexual  indulgence : 
my  best  opportunities  have  been  derived  from  post  mortem  exami- 
nations, in  private,  of  individuals  of  from  fourteen  to  twenty,  where 
the  virgin  state  had  been  preserved.  When  an  ovarium  of  the 
latter  kind  can  be  got,  by  cutting  through  the  tunica  albuginea 
simply,  and  then  tearing  open  the  organ,  it  will  be  found  to  consist 
of  a spongy  fibrous  tissue,  abundantly  furnished  with  blood  vessels 
from  the  spermatic  artery  and  vein.  In  this  spongy  tissue,  called 
Stroma,*  are  from  fifteen  to  twenty  spherical  bodies,  the  Graafian 
vesicles,  ( Ovula  Graajiana ,)  according  to  the  commonly  received 
opinion ; but  in  an  ovarium  exhibited  to  me  by  the  late  Dr.  John 
Hopkinson,  there  were  thirty-six  distinct  vesicles.  They  vary  in 
size  from  half  a line  to  three  lines  in  diameter ; the  larger  ones  are 
nearer  the  surface,  and  from  having  caused  the  absorption  of  the 
tunica  albuginea,  may  sometimes  be  seen  through  the  peritoneal 
coat,  and  give  to  the  surface  of  the  ovarium  an  embossed  condition. 
The  vesicles  contain  a transparent  fluid  having  within  it  the  rudi- 
ments of  the  embryo.  As  the  vesicles  are  evolved  they  advance 
from  the  centre  to  the  circumference.  Their  parietes  are  thin,  trans- 
parent, and  have  creeping  through  them  minute  arterial  and  venous 


By  von  Baer,  from  its  being  a bed  (stratum.) 
13* 


142 


FEMALE  ORGANS  OF  GENERATION. 


ramifications.  The  bed  of  the  ovarium  in  which  a vesicle  reposes 
is  called  the  calyx. 

To  Von  Baer*  belongs  the  merit  of  discerning  first  the  ovulum 
of  man  and  of  mammalia  in  the  Graafian  vesicle.  The  Ovulum  occu- 
pies but  a very  small  part  of  the  cavity  of  the  Graafian  vesicle,  the 
remainder  being  filled  with  an  albuminous  fluid  in  which  micro- 
scopic granules  float.  By  discharging  the  fluid  from  a Graafian 
vesicle,  the  Ovulum  can  with  a simple  lens  be  detected  in  a globu- 
lar form  and  floating  in  this  fluid.  By  flattening  out  this  little  globe 
under  a thin  plate  of  glass,  and  then  examining  with  a compound 
microscope,  it  will  be  seen  that  it  consists  of  a transparent  membrane 
containing  a Vitellus  or  yolk  made  of  granules  or  cells  and  fat  glo- 
bules. 

Within  the  above  vitelline  membrane  is  placed  the  Germinal  vesi- 
cle of  the  human  subject,!  being  about  V j of  a line  in  diameter. 
This  vesicle  has  also  the  germinative  spot,  macula  germinativa  of 
Wagner,  which  is  from  the  jis  to  tnta  of  a line  in  diameter. 

The  Ovula  Graafiana  seldom  project  much  on  the  surface  of  the 
ovarium  in  the  human  subject;  but  in  other  animals,  as  the  common 
hen,  they,  upon  being  developed,  stand  out  so  much  as  to  resemble 
a cluster  of  berries  each  attached  by  its  pedicle,  and  surrounded  by 
its  two  appropriate  sacs.  These  sacs  constitute  what  are  called  the 
capsule  of  the  ovum  or  the  ovisac.  Upon  the  inner  surface  of  this 
capsule,  according  to  the  observation  of  Schwann,  is  to  be  found  a 
layer  of  epithelial  cells  in  the  different  classes  of  animals,  as  for  ex- 
ample, in  the  ovicapsules  of  fish,  and  in  the  Graafian  vesicles  or 
ovules  of  mammalia.  The  existence  of  these  epithelial  cells  is  con- 
sidered as  proof  positive  of  the  sameness  of  the  membrane  in  what- 
ever animals  it  may  be  examined  ; and,  therefore  that  the  ovicapsules 
of  oviparous  animals  are  identical  with  the  Graafian  vesicles  or  ovula 
of  mammalia.  The  stages  of  development  in  an  egg  are,  therefore, 
simply  the  expression  of  what  occurs  also  in  a Graafian  vesicle. 

Within  the  ovicapsule  of  Birds  is  the  yolk  (vitellus)  surrounded 
by  its  membrane  called  vitelline,  which  being  at  first  in  contact  with 
the  capsule,  is  afterwards  separated  from  it  in  many  animals  by  a well 
marked  and  large  interval.  The  yolk  is  formed  of  fine  cells  con- 
taining granules  and  oil  globules. 

* Muller,  p.  14G9. 

f Discovered  by  Coste  in  1834,  and  more  distinctly  explored  by  Valentine 
and  Bernhardt.  Muller,  p.  1471. 


THE  OVARIES. 


143 


In  the  substance  of  the  yolk  is  the  vesicle  of  Purkinje,  or  the  Ger- 
minal vesicle.  This  vesicle  contains  a transparent  fluid,  and  has 
on  it  a nucleus,  called  the  macula  germinativa.  This  vesicle  in  the 
fully  formed  ova  of  the  oviparous  vertebrata  is  imbedded  in  a disk- 
shaped layer  of  granular  substance,  called  the  germ  disk.  The  ger- 
minal vesicle  is  finally  lost  by  commingling  with  the  granular  matter 
of  the  germ  disk,  in  which  the  first  rudiments  of  the  embryo  are 
formed. 

Upon  the  ovum  leaving  the  ovarium  in  a bird  it  has  to  pass  through 
the  oviduct,  and  in  doing  so  receives  as  a deposite  upon  it  the  white 
or  albumen,  and  subsequently  the  shell  which  is  also  due  to  the  se- 
cretory action  of  the  oviduct.* 

The  analogy  is  thus  seen  to  be  striking  between  the  evolution  of  a 
common  egg  and  the  ovule  of  the  human  subject,  found  in  the 
Graafian  vesicle. 

A very  remarkable  point,  mentioned  by  Carus,  is  that  all  the 
essential  parts  of  the  ovulum  can  be  detected  in  the  ovary  of  the 
mature  embryo  of  the  human  subject  or  of  mammiferous  animals, 
hence  the  preparation  for  a new  generation  seems  to  begin  at  a very 
early  period  of  life. 

When  an  ovulum  is  discharged  from  a Graafian  vesicle  the  latter 
and  the  surrounding  calyx  open  in  a stellated  line:  this  line  of  de- 
hiscence or  gaping  is  in  birds  preceded  by  a whitish  arched  band 
called  the  stigma,  which  indicates  the  place  for  the  escape  of  the 
ovum.  There  appears  to  be  some  analogy  in  this  with  the  spon- 
taneous fissure  of  the  rind  or  bur  of  certain  fruits. 

Upon  the  escape  of  the  contents  of  the  Graafian  vesicle  the  latter 
is  first  filled  with  coagulating  lymph  or  blood,  or  rather  undergoes  a 
pullulation  from  its  interior  surface,  so  as  to  form  a body  called  the 
Corpus  Luteum,  which  being  after  a while  absorbed  the  vesicle 
collapses  and  shrivels,  and  the  stigma  then  remains  permanently  as 
a stellated  cicatrix.  Sometimes  the  entire  surface  of  the  ovarium  is 
marked  with  those  stigmata. 

The  phenomena  attending  the  formation  of  the  corpus  luteum 
have  elicited  great  interest,  of  late  years,  and  many  very  scientific 

* A satisfactory  explanation  of  the  above  process,  according  to  Wagner  and 
others,  is  found  in  Muller’s  Physiol.,  p.  1468.  London,  1842. 


144 


LACTIFEROUS  GLANDS. 


observations  have  been  made  on  the  subject  by  BischofF,* * * §  Wagner, f 
Huschke,j;  and  others. 

The  Organs  of  Generation  in  the  female  are  supplied  with  blood 
principally  from  the  internal  pudic  and  other  branches  of  the  hypo- 
gastric artery:  the  corresponding  veins  run  into  the  hypogastric. 
Their  nerves  come  from  the  sacral  and  from  the  hypogastric  plexus. 
The  arteries  of  the  Ovarium  come  from  the  Spermatic  and  from  the 
uterine.  Former  anatomists  considered  the  spermatic  to  be  the  prin- 
cipal one — the  opinion  is  now  changing  in  favour  of  the  branch  of 
the  uterine.  The  spermatic  veins  discharge  as  in  the  male  sub- 
ject. 

The  Bladder  and  the  Rectum,  with  unimportant  exceptions,  are 
the  same  in  both  sexes.  The  Levator  Ani,  the  Coccygeus,  and  the 
Sphincter  Ani,  are  also  similar.  The  pelvic  aponeurosis  in  the 
female,  besides  connecting  the  bladder  to  the  sides  of  the  pelvis, 
is  attached  to  the  anterior  part  of  the  vagina.  The  triangular  liga- 
ment of  the  urethra  also  exists,  but  under  circumstances  somewhat; 
modified  by  the  close  connexion  of  the  urethra  with  the  vagina. 


CHAPTER  III. 

Of  the  Lactiferous  Glands,  or  Brcasts.§ 

The  Breasts  ( Mammae ) of  the  female  are  intended  for  the  secre-. 
tion  of  milk,  and  thereby  to  maintain  the  connexion  between  mother 
and  infant  for  some  time  after  the  uterine  life  of  the  latter  is  passed. 
All  mammiferous  animals  exercise  this  function : in  birds  there  is  a 
sort  of  substitute  for  it,  in  the  changes  which  take  place  in  the  first 
stomach  or  crop  during  incubation.  In  the  male  subject  there  is, 

* Trait,  de  Develop,  de  L.  Homme.  Paris,  1843. 

f Elements  of  Human  Physiol.  Part  I.  London,  1841. 

4 Traite  de  Splanch-  Paris,  1845. 

§ Anat.  Atlas,  Figs.  404  to  410,  inclusive. 


LACTIFEROUS  GLANDS. 


145 


also,  a small  glandular  body  on  each  side,  which  has  the  same  or- 
ganization as  in  the  female,  but  is  in  miniature,  and  always  remains 
in  a collapsed  state,  with  some  rare  exceptions  ; when  it  has  been 
known  to  expand  in  volume,  and  to  furnish  a secretion,  as  in  the 
female.* 

The  Breasts  are  two  in  number,  one  on  either  side;  they  are 
situated  on  the  same  level,  in  front  of  the  peetoralis  major  muscle, 
and  between  the  arm-pit  and  the  sternum.  They  are  hemispherical, 
and  have  their  base  united  to  the  muscle  by  a thin  lamina  of  loose, 
extensible,  cellular  substance,  containing,  even  in  corpulent  women, 
but  little  fat.  The  skin  which  covers  the  front  of  this  gland  is  very 
fine  and  thin,  so  that  the  blood  which  circulates  in  its  veins  maybe 
readily  seen.  Between  the  skin  and  the  front  surface  of  the  gland, 
there  is  a considerable  thickness  of  cellular  adipose  matter,  which, 
from  its  superabundance  in  some  individuals,  gives  to  them  an  ap- 
pearance of  having  the  glands  enormously  enlarged.  There  is, 
however,  a great  variety  in  the  size  of  the  glandular  structure  itself; 
for,  in  females  who  are  youthful  and  giving  suck,  they  are  much 
larger  than  in  such  as  have  passed  the  period  of  child-bearing,  and 
whose  health  is  impaired.  When  all  the  fatty  matter  has  been  re- 
moved from  a breast,  and  it  is  permitted  to  repose  upon  a table, 
its  hemispherical  shape  disappears,  and  it  then  seems  rather  a 
flattened  circular  disk,  of  from  four  to  five  inches  in  diameter. 

The  mamma  is  of  a very  light  pink  colour  ; and  though  very  flac- 
cid and  yielding  on  being  handled,  its  texture  is  actually  extremely 
tough,  and  is  cut  only  by  much  force.  With  the  exception  of  bone, 

* In  a male  patient,  a resident  in  the  Philadelphia  Alms  House,  the  pheno- 
menon of  a full  evolution  of  the  glandular  structure  in  both  breasts  is  mani- 
fested. The  individual  (James  McIntyre)  is  forty  five  years  of  age;  the  breasts 
are  as  large  as  those  of  a nursing  woman ; but  the  nipples  are  not  proportionately 
evolved.  Though  his  frame  is  robust,  and  well  set,  the  voice  is  feminine  ; his 
external  organs  of  generation  are  about  the  size  of  those  of  a boy  of  fourteen  ot 
fifteen.  Thinking  that  there  might  be  an  internal  state  approaching  to  herma- 
phrodism,  he  informed  me,  on  inquiring,  that  in  earlier  life  be  had  the  common 
inclinations  for  the  female.  He  also  informed  me  that  this  unusual  develop- 
ment took  place  seven  or  eight  years  ago,  owing  to  an  excessive  salivation; 
but,  as  he  has  a reserve  on  the  subject,  this  statement  may,  probably,  be  re- 
ceived with  some  qualifications.  I have  also  seen  a second  case,  in  which  the 
voice  is  weak  and  feminine,  but  the  genital  organs  have  not  been  examined. — 
July,  1826. 


146 


LACTIFEROUS  GLANDS. 


it  dulls  a knife  sooner  than  any  other  tissue  of  the  body.  Its  grosser 
arrangement  consists  in  lobes  of  different  sizes,  united  in  such  a way 
by  cellular  texture,  that,  though  they  can  be  pulled  somewhat  apart, 
they  cannot  be  entirely  separated  without  injury.  These  lobes, 
when  examined  through  the  skin,  give  to  the  gland  a knotted  feel, 
and  are  sometimes  partially  affected  by  inflammation,  so  as  to  be- 
come still  more  distinct.  The  lobes  are  composed  of  Lobuli,  which 
are  resolvable  by  maceration  and  particular  modes  of  treatment,  into 
small  graniform  masses  (acini)  about  the  size  of  millet  seed,  and 
which  contain  the  ultimate  glandular  arrangement.  The  acini  them- 
selves consist  of  very  small  oblong  vesicles,  united  by  cellular 
substance,  and  by  the  common  blood  vessels  ; and  are  said  to  be 
very  apparent  by  the  aid  of  a microscope  in  a lactescent  gland.* 
These  vesicles  (Cellulae  Lactiferee)  have  a diameter  from  ten  to  thirty- 
five  times  greater  than  that  of  the  smallest  capillary  vessel  of  the 
body,f  or  according  to  Krause  from  the  1-27  to  the  1-14  of  a 
line. 

These  vesicles  terminate  by  large  openings  into  the  incipient  ex- 
tremities of  the  lactiferous  ducts,  having  no  particular  conduit  as  in 
the  liver,  the  pancreas  and  the  parotid. 

Each  vesicle  is  surrounded  by  a fine  close  vascular  net-work, 
which  is  displayed  upon  its  walls,  but  according  to  the  opinion  of 
the  day  does  not  discharge  into  it. 

The  Excretory  Ducts  (Ductus  Galadophori , Ladiferi ) of  this  gland 
are  numerous.^  They  are  of  an  arborescent  shape,  and  begin  by 
very  fine  extremities  or  ramuscules  in  the  acini ; the  ramuscules  from 
several  acini  coalesce  into  a larger  branch ; several  branches  unite 
to  form  one  still  larger,  and  so  on,  successively,  until  a lactiferous 
trunk,  constituting  as  it  were,  the  body  of  the  tree,  is  formed  by  this 
assemblage.  These  trunks  vary  considerably  in  size,  according  to 
the  number  of  tributary  branches,  and  having  got  towards  the  centre 
of  the  gland  near  the  nipple,  from  two  to  four  of  them,  according 
to  Cuboli,  run  into  a common  tube  or  root,  called  a Lactiferous 

* Marjolin,  Manual  D’Anat.  J.  F.  Meckel,  Manual  D’Anat. 

f Muller,  loc.  cit.  p.  488. 

X Alex.  Kolpin,  Dis.  Inaug.  de  Struc.  Mam.  Cubolo,  Append,  ad  Sep- 
temd.  Tab.  Santorini.  Girardi,  Append,  ad.  Septemd.  Tab.  Santorini. 


LACTIFEROUS  GLANDS. 


147 


Sinus.  These  Sinuses  are  in  all  about  fifteen : they  are  only  a few 
lines  long,  and  differ  in  size  ; some  not  being  larger  than  one  lacti- 
ferous duct,  while  others  have  a diameter  of  from  two  to  three  lines. 
The  sinus  at  the  end  next  to  the  nipple  terminates  in  a sort  of 
rounded  cul-de-sac ; but  from  the  extremity  of  the  sac  a conoidal 
tube  arises  which  runs  through  the  nipple,  and  conducts  the  milk : 
the  point  of  this  tube  is  very  fine,  and  ends  on  the  top  of  the  nipple. 
This  tube,  from  its  shape,  is  suited  to  the  retention  of  milk ; in  ad- 
dition to  which,  it  is  sometimes  dilated  in  the  middle;  is  curved 
when  the  nipple  is  not  in  a state  of  erection  or  stretched  out,  and 
terminates  by  an  external  orifice,  which  is  so  small  as  to  be  seen 
with  difficulty  by  the  naked  eye. 

The  excretory  ducts  of  the  breast,  under  which  term  maybe  com- 
prehended the  lactiferous  ducts,  the  sinuses,  and  the  conoidal  tubes 
in  the  nipple,  are  formed  by  a soft,  thin,  and  semi-transparent  mem- 
brane, very  capable  of  extension  and  of  contraction.  The  trunks 
generally  go  deeply  through  the  substance  of  the  gland,  and  are  tor- 
tuous, but  do  not  anastomose  laterally  with  one  another ; whence  it 
happens  that  the  lobes  and  lobules  of  the  gland  are  arranged  into 
sections,  each  of  which  has  its  appropriate  excretory  duct.  In  order 
to  make  a complete  injection  of  the  gland,  each  sinus  must  be  sepa- 
rately injected  through  its  conoidal  tube.  This  rule  is  not  of  uni- 
versal application,  as  in  some  experiments  performed  by  the  elder 
Meckel  upon  women  advanced  in  pregnancy  and  during  lactation, 
he  succeeded  in  forcing  mercury  through  one  sinus,  by  its  ramifica- 
tions, into  those  of  another : this  route  was  supposed  to  have  been 
through  the  finest  extremities  of  the  ducts.  The  whole  gland  itself 
may,  however,  from  the  infrequency  of  this  circumstance,  and  from 
the  difficulties  and  partial  condition  of  these  anastomoses,  rather  be 
considered  as  a congeries  of  smaller  glands  kept  distinct  by  the  in- 
terposition of  cellular  substance  between  their  lobes  ; but  joined,  in 
one  respect,  by  having  the  terminations  of  their  excretory  tubes  col- 
lected into  one  bunch  in  the  nipple.  This  latter  circumstance 
seems  to  be  only  a provision  for  the  more  convenient  sucking  of  the 
infant. 

The  excretory  ducts  are  no  where  furnished  with  valves,  which 
accounts  for  the  facility  with  which  they  may  be  injected  backwards 
from  the  nipple.  An  opinion  was  entertained  by  Haller,  and  by 
other  anatomists  after  him,  that  some  of  these  ducts  originate  in  the 


14S 


LACTIFEROUS  GLANDS. 


surrounding  cellular  substance,  but  this  has  been  refuted  by  the  re- 
searches of  Cubolo.  Some  anatomists  have  thought  that  there  is  a 
direct  communication  between  the  ends  of  the  lactiferous  tubes  and 
the  arteries,  veins,  and  lymphatics.  Mascagni,  after  a very  success- 
lul  injection  of  the  gland,  whereby  its  vesicles  were  filled  with  quick- 
silver, not  meeting  with  such  an  occurrence,  was  induced  to  think 
that  when  the  communication  did  happen,  it  was  produced  by 
rupture. 


Terminal  follicles  of 
Mammary  gland,  with 
their  secreting  cells,  a, 
a ,• — b,  b,  the  nuclei. 


Terminal  extremities 
of  milk-duct  in  follicles ; 
from  a mercurial  injec- 
tion, by  Sir  A.  Cooper; 
enlarged  four  times. 


The  membrane  of  the  lactiferous  canals  is  somewhat  yellow,  and 
upon  a transverse  section  of  the  gland  may  be  distinguished  by  its 
colour.  It  is  covered  by  epithelial  cells,  which  are  almost  every 
where  pavement  like,  according  to  Pappenheim  ; upon  their  removal 
he  found  transverse  elastic  fibres,  covered  with  longitudinal  fibres 
and  numerous  cellular  fibres,  but  no  muscular. 


The  Areola , 

In  virgins  is  a rose-coloured  circle,  which  surrounds  the  base  of 
the  papilla  or  nipple.  In  women  who  have  borne  children,  or  in 
those  whose  age  is  advanced,  it  becomes  of  a dark  brown.  The 
skin  of  the  areola  is  extremely  delicate,  and  on  its  surface,  particu- 
larly in  pregnant  or  nursing  females  there  are  from  four  to  ten  tuber- 
cles, which  sometimes  form  a regular  circle  near  its  circumference, 
and  in  other  subjects  are  irregularly  distributed.  Each  of  these 
tubercles  has  near  its  summit  three  or  four  foramina,  which  are  the 
orifices  of  the  excretory  ducts  of  a little  gland  forming  the  tubercle. 
The  areola  consists  of  a spongy  tissue  beneath  which  there  is  no  fat ; 


AREOLA. 


149 


it  is  susceptible  of  distention  during  lactation,  or  from  particular  ex- 
citement. 

The  greater  number  of  anatomists  have  considered  these  tuber- 
cles as  intended  only  for  the  secretion  of  an  unctuous  fluid  which 
lubricates  the  areola  and  nipple,  and  protects  them  from  excoriation 
by  the  sucking  of  the  infant.  It  is  said,  however,*  that  when  some 
time  has  elapsed  after  a repast,  or  when  there  has  been  a long  inter- 
val to  the  nursing  of  the  child,  milk  flows  from  them  abundantly ; 
but  that  in  reverse  circumstances  a transparent,  limpid  fluid  is  dis- 
tilled in  small  drops  ; all  of  which  would  tend  to  prove  that  they  are 
of  the  same  nature  with  the  mammae  themselves,  being  only  smaller. 
In  addition  to  them,  it  is  said  that  the  areola  and  the  nipple  are 
furnished  with  a great  number  of  sebaceous  glands,  which  do  not 
elevate  themselves  above  the  surface,  and  which  may  be  found  on 
and  near  the  tubercles. 


The  Papilla , 

Is  the  truncated  cone  in  the  centre  of  the  mamma,  of  the  same 
colour  with  the  areola,  and  surrounded  by  it.  The  lactiferous  tubes 
terminate  on  its  extremity.  It  is  collapsed  and  in  a very  pliable 
state  for  the  most  part,  but  when  excited  it  swells,  becomes  more 
prominent,  and  of  a deeper  colour.  Its  skin  is  rough,  and  provided 
with  numerous  and  very  small  papillae.  Its  internal  structure  con- 
sists of  the  extremities  of  the  lactiferous  tubes  united  by  condensed 
cellular  membrane. 

The  mamma  is  supplied  with  blood  from  the  external  thoracic, 
^tercostal,  and  the  internal  mammary  arteries.  Its  veins  attend 
their  respective  arteries.  The  nerves  come  from  the  axillary  plexus 
and  from  the  intercostals.  The  lymphatics  run  into  the  internal 
mammary,  intercostal,  and  axillary  trunks. 

Among  the  anomalies  affecting  this  gland  is  the  existence  of  a 
supernumerary  nipple — but  sometimes  there  is  a second  gland  entire 
on  one  or  both  sides,  and  commonly  placed  below  the  normal  one. 

* J.  F.  Meckel. 


Vol.  II.— 14 


BOOR  VII 


OF  THE  ORGANS  OF  RESPIRATION. 

The  Organs  of  Respiration  are  the  Larynx,  the  Trachea,  and  the 
Lungs. 


CHAPTER  I. 

Of  tlie  Larynx.* 

The  Larynx  is  an  irregular  cartilaginous  tube  that  forms  the  upper 
extremity  of  the  windpipe.  It  is  situated  immediately  below  the  os 
hyoides  and  the  root  of  the  tongue,  where  it  may  be  felt  readily 
through  the  integuments,  and  by  its  prominence  contributes  to  the 
outline  of  the  neck.  Its  position  is  such,  that  it  is  bounded  behind 
by  the  pharynx,  which  is  interposed  between  it  and  the  vertebrae  of 
the  neck;  and  laterally  by  the  primitive  carotid  arteries  and  the  in- 
ternal jugular  veins.  It  gives  passage  to  the  air  which  is  inhaled 
into  the  lungs  or  exhaled  from  them,  and  also  contributes  essentially 
to  the  production  of  the  voice.  Its  special  use,  on  the  latter  oc- 
casion, has  induced  some  anatomists  to  give  it  a description  apart 
from  that  of  the  other  organs  of  respiration ; but  as  the  function  of 
voice  is  subordinate  to  that  of  respiration,  I have  preferred  an  ob- 
servance of  its  most  natural  and  local  connexions. 

Five  distinct  cartilages  form  the  skeleton  of  this  structure : the  os 


* Anat.  Atlas,  Figs.  411  to  424,  inclusive. 


152 


ORGANS  OF  RESPIRATION. 


hyoides,  which  is  common  to  it  and  to  the  root  of  the  tongue,  also 
contributes  to  its  superior  part,  in  a manner  which  will  lie  presently 
mentioned.  The  cartilages  are  one  Thyroid,  one  Cricoid,  one 
Epiglottis,  and  two  Arytenoid. 

The  Thyroid  Cartilage  ( Cartilage  Thyroidea)  is  the  largest  of  the 
five,  and  being  placed  about  one  inch  below  the  os  hyoides,  pro- 
duces in  the  upper  part  of  the  neck  the  prominence  called  Pomum 
Adami.  It  consists  in  two  lateral  halves,  which  in  most  individuals 
are.  perfectly  symmetrical,  and  are  continuous  with  each  other  on  the 
middle  line  of  the  body.  These  two  sides  form  at  their  line  of  junc- 
tion an  angle  projecting  forwards,  and  resembling  that  of  the  canal 
or  hydraulic  gate : the  superior  part  of  the  angle  is  more  prominent 
than  the  inferior;  particularly  in  the  male  subject.  The  sides  of 
this  body  lean  outwards,  by  which  its  transverse  diameter  above  is 
increased. 

The  angle  is  terminated  above  by  a deep  notch,  from  which  the 
superior  margin  begins  to  form  a curvature,  on  either  side,  like  the 
letter  S;  the  inferior  margin  is  also  somewhat  curved,  but  to  a 
smaller  degree.  The  posterior  margin  of  each  half  is  nearly 
straight,  but  is  elongated  above,  with  the  aid  of  the  upper  margin 
into  a long  process,  the  Cornu  Majus;  and  below  with  the  aid  of 
the  inferior  margin,  into  another  process  not  so  long,  Cornu  Minus. 

The  internal  surface  of  each  half  of  the  thyroid  cartilage  is  flat; 
but  the  exterior  surface  is  slightly  marked  by  the  sterno-thyroid  and 
the  thyreo-hyoid  muscles. 

The  Cricoid  Cartilage  ( Cartilago  Cricoidea ) is  placed  below  the 
thyroid,  and  is  the  base  of  the  larynx.  It  is  an  oval  ring,  of  an  un- 
equal thickness  and  breadth. 

Its  inferior  margin  is  nearly  straight  and  horizontal,  and  is  con- 
nected to  the  first  ring  of  the  trachea ; it  is  also  thinner  than  the 
superior:  the  latter  is  very  oblique,  and  rises  from  before  backwards 
and  upwards  so  abruptly,  that  the  breadth  of  the  cricoid  cartilage 
behind  becomes  three  times  as  great  as  it  is  in  front,  under  the  in- 
ferior margin  of  the  thyroid  cartilage.  The  superior  margin  has  on 
each  side,  behind,  a little  head,  or  convexity,  which  receives  the 
base  of  the  corresponding  arytenoid  cartilage,  and  forms  with  it  a 
ball  and  socket  joint. 

The  interior  surface  of  the  cricoid  cartilage  is  smooth,  and  co- 


THE  LARYNX. 


153 


vered  by  the  lining  membrane  of  the  larynx.  Its  exterior  surface  is 
flattened  behind  on  each  side,  by  the  posterior  crico  arytenoid  mus- 
cles ; it  is  marked  also  laterally  by  other  muscles,  and  by  the  infe- 
rior cornu  of  the  thyroid  cartilage. 

The  cricoid  cartilage  is  embraced  by  the  inferior  margin  of  the 
thyroid,  but  in  such  a way  that  a triangular  interval  is  left  in  front 
between  the  two  cartilages. 

The  Arytenoid  Cartilages  ( Cartilagines  Jirytcenoidece ) resemble 
triangular  pyramids  curved  backwards,  and  are  about  six  lines  long. 
They  are  placed  on  the  upper  margin  of  the  cricoid  cartilage  be- 
hind. The  anterior  face  of  each  is  uneven,  and  divided  into  two 
concavities  ; the  posterior  face  forms  a single  cylindrical  concavity  ; 
and  the  internal  face,  by  which  it  approximates  its  fellow,  is  nearly 
flat.  When  joined  together,  the  two  cartilages  resemble  the  mouth 
or  spout  of  a pitcher,  from  whence  their  name.  Their  bases  are 
hollowed  into  a small  glenoid  cavity,  for  articulating  with  the  cricoid 
cartilage. 

A synovial  capsule  is  reflected  over  the  articulation,  between  the 
arytenoid  and  the  cricoid  cartilage : this  capsule  is  strengthened  by 
a few  scattered  ligamentous  fibres. 

The  Epiglottis  Cartilage  ( Epiglottis ) is  situated  on  the  posterior 
face  of  the  base  of  the  os  hyoides,  being  enclosed  partially  by  the 
two  sides  of  the  thyroid  cartilage.  Its  general  form  is  that  of  an 
oval  disk ; the  upper  margin  of  it  is  thin  and  rounded,  partially 
curled  forwards,  and  the  lower  part  is  elongated  into  a pedicle 
which  adheres  to  the  entering  angle  of  the  thyroid  cartilage.  Its 
lateral  margin  is  attached  by  a-  thin  elastic  membrane  to  the  entire 
length  of  the  upper  thyreo  arytenoid  ligament. 

Its  surfaces,  though  nearly  flat,  are  not  fully  so ; for,  anteriorly, 
it  forms  a cylindrical  convexity,  and  posteriorly,  a cylindrical  con- 
cavity, from  side  to  side.  When  nicely  stripped  of  its.  covering,  a. 
number  of  very  small  foramina  is  seen  to  exist  in  it,  which  are 
considered  to  give  passage  principally  to  the  ducts  of  muciparous 
glands.  Its  connexions,  aided  by  its  natural  elasticity,  keep  it  in  a 
vertical  attitude  behind  the  base  of  the  tongue  ; its  rounded  margin 
is  elevated  above  the. latter,  and  overlooks  it. 

In  addition  to  the  preceding  cartilages,  there  are  always  two,  and 

14* 


154 


ORGANS  OF  RESPIRATION. 


sometimes  four  others.  On  the  top  of  each  arytenoid  is  to  be  found 
one,  (Corniculum  Laryngis;)  it  is  somewhat  triangular  and  elongated: 
its  inferior  face  is  attached  by  a few  ligamentous  fibres  to  the  end 
of  the  arytenoid  ; it  is  included  in  the  soft  parts,  and  is  very  move- 
able.  'fhe  others,  when  they  exist,  which  is  rare,  are  found  on  the 
margin  of  the  glottis,  in  the  duplicating  of  the  membrane  which  is 
extended  from  the  side  of  the  epiglottis,  to  the  tip  of  the  arytenoid 
cartilage. 

From  the  whole  superior  margin  of  the  thyroid  cartilage  included 
between  its  greater  cornua,  there  proceeds  upwards  a thin  lamina  of 
somewhat  condensed  cellular  substance,  which  is  attached  to  the 
inner  margin  of  the  base  and  of  the  cornua  of  the  os  hyoides  their 
Avhole  length.  It  fills  completely  the  space  between  the  os  hyoides 
and  the  thyroid  cartilage.  This  membrane  is  called  the  middle 
fhyreo-hyoid  Ligament,  ( Ligament  Thyreo-Hyoid.  Medium ,)  though 
its  ligamentous  character  is  by  no  means  well  developed.  It  com- 
pletes the  periphery  of  the  larynx  in  the  space  alluded  to,  and,  from 
its  thin  yielding  nature,  presents  no  obstacle  to  the  motions  of  the  os 
hyoides  and  of  the  thyroid  cartilage  upon  each  other. 

The  posterior  margin  of  this  membrane,  on  each  side,  is  bounded 
by  a long,  rounded,  fibrous  chord,  the  Lateral  Thyreo-Hyoid  Liga- 
ment, ( Ligamentum  Thyreo-Hyoideum  Later  ale.)  The  latter  is  ex- 
tended from  the  cornu  major  of  the  thyroid  cartilage  to  the  tubercu- 
lated  extremity  of  the  os  hyoides,  and  frequently  contains,  about  its 
centre,  a small  oval  cartilage  or  bone,  ( Cartilago  Triticea ,)  not 
quite  so  large  ag>  a grain  of  wheat. 

Immediately  under  the  body  of  the  os  hyoides,  between  its  con- 
cave face  and  the  middle  thyreo-hyoid  ligament,  is  a small  sac  or 
cell  formed  between  the  laminae  of  this  ligament,  and  frequently  ex- 
tending itself  downwards  as  far  as  the  notch  of  the  thyroid  cartilage, 
it  is  flat,  about  four  or  five  lines  in  its  transverse  diameter,  and  pre- 
sents a shining  surface.  I have  never  seen  a fluid  in  it  in  the  na- 
tural state ; its  secretion,  however,  sometimes  becomes  excessive, 
and  it  is  then  elongated  downwards  over  the  front  of  the  thyroid  and 
of  the  cricoid  cartilage,  as  far  as  the  isthmus  of  the  thyroid  gland. 
In  this  state  it  frequently  forms  a small  fistulous  opening,  at  its  lower 
end,  through  the  skin  ; and  which  is  marked  by  a fold  of  the  latter 
across  the  neck.  The  true  pathology  of  the  disease  was  first  pointed 
out  by  the  late  Dr.  Physick,  who  cured  it,  in  some  cases,  by  the  in-- 
troduction  of  lunar  caustic,  and  in  others  by  extirpation. 


THE  LARYNX. 


155 


The  lateral  Crico-Thyroid  Ligament  attaches  the  Cornu  minus  or 
inferior  horn  of  the  thyroid  cartilage  to  the  side  of  the  cricoid ; there 
is  not  unfrequently  an  articular  cavity  within  its  circle.  This  junc- 
tion is  the  centre  of  the  very  limited  rotatory  motion  of  the  thyroid 
upon  the  cricoid  cartilage. 

The  interval  in  front  between  the  thyroid  and  the  cricoid  cartilages 
is  filled  by  a ligament  adhering  to  its  margins  called  the  Middle 
Crico-Thyroid,  to  distinguish  it  from  the  ligamentous  junction  be- 
tween the  inferior  cornua  of  the  thyroid,  and  the  sides  of  the  cricoid. 
The  middle  ligament  has  some  small  apertures  in  it  for  the  passage 
of  blood  vessels  and  of  nerves.  It  is  the  part  commonly  cut  in  the 
operation  of  laryngotomy. 

The  Thyreo-Arytenoid  Ligaments  are  two  in  number,  on  each 
side  of  the  larynx  ; one  above  the  other,  at  the  distance  of  three 
lines.  The  inferior  is  extended  from  the  anterior  angle  of  the  base 
of  the  arytenoid  cartilage  to  the  inferior  part  of  the  entering  angle  of 
the  thyroid,  and,  by  converging  towards  its  fellow,  is  inserted  there 
in  contact  with  it.  Its  fibrous  structure  is  very  distinct.  It  also 
bears  the  name  of  vocal  chord  (Ligamentum  Vocale,)  from  its  border- 
ing the  rima  glottidis.  The  superior  thyreo-arytenoid  ligament  arises 
from  the  middle  of  the  anterior  edge  of  the  arytenoid  cartilage,  and  is 
also  inserted  into  the  entering  angle  of  the  thyroid  ; it  is  more  distant 
from  its  fellow  than  the  lower  one  is,  and  goes  almost  parallel  with 
it ; so  that  the  opening  between  the  two  upper  is  both  larger  and 
more  like  an  oblong,  than  it  is  between  the  two  lower.  Its  fibrous 
structure  is  less  distinct  than  that  of  the  lower.  Both  the  upper  and 
the  lower  ligaments  are  covered  by  a reflection  of  the  lining  mem- 
brane of  the  larynx,  and  are  small,  round  fibrous  bands,  which  are 
rendered  more  or  less  tense  by  the  action  of  the  small  muscles  of  the 
larynx. 

The  superior  thyreo-arytenoid  ligament  is  attached,  in  its  whole 
length,  by  a triangular  fibro-muscular  layer  to  the  pedicle  and  side  of 
the  epiglottis : the  posterior  margin  of  this  layer  is  distinctly  mus- 
cular, and  must  have  the  effect  of  drawing  the  ligament  upwards, 
hence  this  ligament  is  in  an  arched  line. 

Lauth  has  described  a band  of  radiating  elastic  fibres  which  leaves 
the  thyroid  cartilage,  between  the  vocal  chords,  and  expands  so  as 
to  be  attached  to  the  superior  margin  of  the  Cricoid  cartilage, — to 


/ 


156 


ORGANS  OF  RESPIRATION. 


the  crico-thyroid  ligament,  — to  the  arytenoid  cartilage  and  its  articu- 
lation,— and  also  to  the  lower  and  upper  thyreo-arytenoid  ligaments.* 

There  are  several  pairs  of  muscles  belonging  to  the  larynx. 

1.  The  Thyreo-IIyoideus,  as  observed  in  the  former  account  of 
this  muscle,  looks  like  a continuation  of  the  sterno-thyroideus.  It 
arises,  obliquely,  from  the  side  of  the  thyroid  cartilage  by  the  ridge, 
there ; and  running  upwards,  it  is  inserted  into  a part  of  the  base, 
and  into  nearly  all  the  cornu  of  the  os  hyoides. 

When  the  thyroid  cartilage  is  fixed,  it  draws  down  the  os  hyoides ; 
but  when  the  latter  is  fixed,  it  draws  up  the  thyroid  cartilage. 

2.  The  Crico-Thyroideus  arises,  tendinous  and  fleshy,  from  the 
anterior  lateral  surface  of  the  cricoid  cartilage,  and  passes-  upwards 
and  backwards,  to  be  inserted  into  the  inferior  cornu  of  the  thyroid 
cartilage,  and  into  the  adjacent  part  of  its  inferior  edge. 

Use,  to  draw  these  cartilages  obliquely  together. 

3.  The  Crico-Arytenoideus  Posticus  arises  from  the  back  of  the 
cricoid  cartilage,  occupying  its  excavation,  and  is  inserted  into  the 
posterior  part  of  the  base  of  the  arytenoid  cartilage. 

It  draws  the  arytenoid  backwards,  and  makes  the  ligaments  tense., 

4.  The  Crico-Arytenoideus  Lateralis  arises  from  the  side  of  the 
cricoid  cartilage,  and  is  inserted  into  the  side  of  the  base  of  the  ary- 
tenoid. 

Use,  to  draw  the  latter  outwards,  and  open  the  chink  of  the. 
glottis. 

5.  The  Thyreo-Arytenoideus  arises  from  the  posterior  face  of  the 
thyroid  cartilage,  near  its  angle,  and  the  middle  crico-thyroid  liga- 
ment, and  is  inserted  into  the  anterior  edge  of  the  arytenoid  cartilage. 

Use,  to  relax  the  ligaments  of  the  glottis. 

G.  The  Arytenoideus  Obliquus  arises  from  the  base  of  one  ary-, 
tenoid  cartilage,  and  is  inserted  into  the  tip  of  the  other.,  It  is  a 
very  small  fasciculus,  and  sometimes  only  one  muscle  exists. 

Use,  to  close  the  chink  of  the  glottis. 

* Huschke  Traite  de  Splanch.  p.  224.  Paris,  1845.  Also  Muller  Physiol,  p. 
1005,  who  considers  that  an  extension  or  lamina  of  the  same,  covers  the  outer 
face  of  the  ventricle  of  the  Larynx. 


THE  LARYNX. 


157 


7.  The  Arytenoideus  Transversus  is  always  a single  muscle  which 
arises  posteriorly  from  the  whole  length  of  one  arytenoid  cartilage, 
excepting  a little  part  of  the  tip,  and  is  inserted,  in  a corresponding 
manner,  into  the  other.  It  fills  up  the  cylindrical  concavity  of  the 
arytenoid  cartilages. 

Use,  to  close  the  chink  of  the  glottis. 

8.  The  Thyreo-Epiglottideus  consists  in  a few  fibres,  and  arises 
from  the  posterior  face  of  the  thyroid  cartilage  near  its  entering  angle. 
It  is  inserted  into  the  side  of  the  epiglottis. 

Use,  to  draw  the  epiglottis  downwards. 

9.  The  Aryteno-Epiglottideus  consists  also  in  a few  indistinct 
fibres,  and  arises  from  the  superior  lateral  parts  of  the  arytenoid  car- 
tilage. It  is  inserted  into  the  side  of  the  epiglottis. 

Use,  to  draw  the  epiglottis  downwards. 

These  last  two  muscles  are  generally  so  small  and  undefined,  that 
they  cannot  be  satisfactorily  distinguished  from  the  adjacent  soft 
parts. 

On  the  posterior  face  of  the  thyroid  cartilage  ; of  the  middle  thyreo- 
hyoid  ligament ; and  on  each  side  of  the  epiglottis  cartilage,  surroun- 
ding its  lower  part  with  the  exception  of  its  posterior  face,  there  is 
an  accumulation  of  cellular  and  adipose  substance.  In  the  lower 
part  of  this  substance  there  are  several  small  glandular  bodies,  some- 
times insulated  and  sometimes  collected  together,  which  are  con- 
sidered to  detach  their  prolongations  into  the  foramina  of  the  epi- 
glottis cartilage,  and  seem  to  open  thereby  on  its  laryngeal  surface  ; 
they  are  mucous  glands. 

The  Arytenoid  Gland,  which  is  also  muciparous,  is  situated  in 
front  of  the  arytenoid  cartilage,  in  the  duplicature  of  the  mucous 
membrane  which  passes  from  the  side  of  the  epiglottis  cartilage  to 
the  arytenoid.  It  is  a small  body  of  a grayish  colour,  resembling 
the  letter  L,  and  consists  in  distinct  grains ; it  is  supposed  to  have 
its  excretory  ducts  opening  into  the  larynx.  It  is  frequently 
wanting. 

The  Interior  Face  of  the  Larynx  is  lined  by  a mucous  membrane, 
continuous  above  with  that  of  the  mouth  and  pharynx,  and  below 


158 


ORGANS  OF  RESPIRATION. 


with  that  of  the  trachea.  Where  it  is  reflected  from  the  base  of  the 
tongue  to  the  epiglottis  cartilage,  it  forms,  as  described,  a well- 
marked  vertical  fold  or  frsenum  in  front  of  the  middle- of  the  latter, 
and  on  each  side  of  this  middle  fold  there  is  another,  not  so  distinct, 
but  varying  in  different  subjects.  Beneath  the  middle  fold  is  a 
strong  fibro-muscular  connexion  with  the  root  of  the  tongue.*  The 
three  folds  form  two  pouches  in  front  of  the  epiglottis,  in  which  food 
is  sometimes  lodged.  The  mucous  membrane  also  forms  the  dupli- 
cature  on  each  side  already  alluded  to,  which  passes  from  the  lateral 
part  of  the  epiglottis  cartilage  to  the  arytenoid  of  the  same  side  of 
the  body.  This  duplicature  forms  the  superior  boundary  of  the 
cavity  of  the  larynx,  and  is  very  soft  and  extensible,  permitting  freely 
the  epiglottis  to  be  depressed  and  to  rise  again  into  its  vertical  posi- 
tion. The  duplications  of  the  two  sides,  taken  together,  form  ari 
oblong  oval  opening  into  the  larynx,  passing  very  obliquely  upwards 
and  forwards  to  the  epiglottis,  and  terminated  behind  by  a notch 
between  the  cornicula  laryngis.  At  the  latter  place  the  mucous 
membrane  is  wrinkled  and  loose,  so  as  to  permit,  by  its  extensi- 
bility, free  motion  to  the  arytenoid  cartilages. 

After  adopting  the  preceding  arrangement,  the  lining  membrane 
of  the  larynx  passes  downwards ; it  covers  smoothly  the  posterior 
face  of  the  epiglottis,  adhering  closely  to  it ; but,  when  it  reaches 
the  thyreo-arytenoid  ligaments,  it  is  tucked  in  between  the  upper 
and  the  lower  one,  so  as  to  form,  on. either  side,  an  oblong  pouch, 
the  bottom  of  which  is  broader  than  its  orifice  between  the  ligaments. 
This  pouch  is  the  ventricle  of  Galen,  or  of  Morgagni,  or  of  the 
larynx  ;f  it  projects  into  the  fatty  glandular  matter  on  the  posterior 
face  of  the  thyroid  cartilage,  and  has  its  base  resting  on  the  thyreo- 
arytenoid  muscle.  Its  superior  end  reaches  almost  as  high  as  the 

* A muscle  of  a triangular  shape  has  lately  been  observed  by  the  English 
anatomists,*  situated  in  front  of  the  epiglottis,  passing  to  it  from  the  base  of 
the  os  hyoides  : it  is  called  Hyo-Epiglottideus.  The  observations  on  its  ex- 
istence have  not  yet  been  repeated  sufficiently  often  to  determine  whether  it 
belongs  to  the  normal  structure  of  the  body  or  not,  and  in  my  own  dissections, 
for  the  purpose  of  ascertaining  its  existence,  it  has  not  occurred.  Albinus, 
Soemmering,  and  others,  speak  of  the  occasional  existence  of  muscular  fibres 
there.  A strong  muscle  is  found  there  in  the  lower  animals,  as  stated  in  the 
description  of  the  tongue,  vol.  1st. 

f Anat.  Atlas,  Fig.  420. 


* Am.  Med.  Journ.  vol.  v.  p.  475. 


THE  LARYNX. 


159 


upper  margin  of  the  thyroid  cartilage,  and  it  has  some  small  fasci- 
culi of  muscular  fibres  on  its  belly  which  seem  appropriated  to  its 
use.  This  pouch  is  in  fact  divided  into  two  compartments,  an  upper 
and  lower ; the  lower  is  oblong  and  horizontal,  being  between  the 
thyreo-arytenoid  ligaments ; the  higher  portion  is  a compressed 
spheriform  sac,  and  communicates  with  the  lower  by  a narrow'  neck. 
The  continuation  of  the  lining  membrane  of  the  Larynx  afterwards 
lines  smoothly  the  cricoid  cartilage,  and  abounds  there  in  mucous 
follicles. 

That  portion  of  the  larynx  which  is  formed  by  the  thyreo-aryte- 
noid ligaments,  and  the  pouches  between  them,  is  the  structure 
essential  to  the  formation  of  voice.  The  opening  between  the  two 
lower  ligaments,  is  the  Rima  Glottidis,  and  the  space  between  the 
upper  ligaments  and  the  duplicature  of  the  mucous  membrane  pass- 
ing from  the  arytenoids  to  the  epiglottis  cartilage,  may  be  termed  the 
Glottis. 

The  Epiglottis  Cartilage  is  principally  useful  in  preventing  articles 
of  food  from  falling  into  the  glottis,  either  in  swallowing  or  in  vo- 
miting. The  strength  of  its  muscles,  hownver,  does  not  seem  to  be 
sufficient  to  draw  it  down  over  the  glottis,  as  many  physiologists 
suppose ; on  the  contrary,  I am  induced  to  believe  that  the  glottis 
is  rather  drawn  upwards  to  it.  If,  on  any  occasion,  it  be  depressed 
or  bent  down  over  the  glottis,  the  position  must  be  caused  by  me- 
chanical pressure  from  the  bulk  of  the  article  swallowed.  But  the 
latter  explanation  is  not  sufficient  to  account  for  the  swallowing  of 
fluids,  or  of  a very  small  body  as  a pill  or  a crumb  of  bread. 

Impressed  with  these  objections,  and  unsatisfied  with  the  com- 
mon theory,  I had  an  opportunity,  in  a dissection  many  years  ago, 
of  witnessing  a position  of  these  parts  which  afforded  a satisfactory 
explanation.  The  subject  was  a robust,  muscular  man,  who  had 
died  suddenly.  The  upper  orifice  of  the  glottis  was  closed  and  pro- 
tected, but  by  an  arrangement  precisely  the  reverse  of  the  received 
opinion;  for  the  epiglottis,  retaining  its  naturally  erect  position,  with 
a slight  inclination  backwards,  had  the  opening  of  the  glottis  drawn 
up  so  as  to  come  in  contact  wfith  its  posterior  face.  The  cricoid 
cartilage,  as  has  been  mentioned,  slopes  on  its  superior  margin  up- 
wards and  backwards  ; the  front  surfaces  of  the  arytenoid  cartilages, 
in  their  natural  position,  are  nearly  on  a line  with  this  slope,  or  a 
continuation  of  it ; the  whole  may,  therefore,  be  considered  in  the 
light  of  an  oblique  plane,  rising  up  behind  the  epiglottis  cartilage. 


160 


ORGANS  OF  RESPIRATION. 


By  a very  slight  additional  elevation  of  this  plane  along  with  the 
rotatory  motion  of  the  thyroid  cartilage  upon  its  lesser  cornua,  the 
plane  is  caused  to  come  in  contact  with  the  posterior  face  of  the 
epiglottis,  and  thereby  to  close  the  upper  opening  of  the  glottis. 

The  principal  agents  in  this  motion  are  the  thyreo-hyoid  muscles, 
the  contraction  of  which,  causing  the  larynx  to  ascend,  the  opening 
of  the  glottis  is  brought  up  behind  the  epiglottis,  and  thereby  secured 
from  the  introduction  of  food  into  it.  Whether  the  food  be  passed 
from  the  mouth  into  the  stomach,  as  in  swallowing,  or  from  the  sto- 
mach into  the  mouth,  as  in  vomiting,  is  equally  unimportant ; and 
the  security  is  the  same,  whether  the  article  be  small  or  large,  fluid 
or  solid.  Several  years  ago,  I dissected  a gentleman  who  had 
symptoms  of  sore  throat  with  swelling  of  the  neck,  superadded  to 
those  of  pulmonary  consumption : during  the  existence  of  his  sore 
throat,  in  addition  to  the  usual  difficulty  of  Swallowing,  he  was  fre- 
quently affected  in  the  act,  with  strangulation  to  an  alarming  and 
distressing  degree.  In  the  dissection,  it  was  found  that  an  abscess, 
of  considerable  extent,  existed  between  the  os  hyoides  and  the  thy- 
roid cartilage,  and  involved  the  thyreo-hyoid  muscles.  Without 
knowing  at  the  time  the  value  of  this  observation,  I am  now  per- 
suaded that  the  strangulation  arose  from  the  inactivity  of  the  thyreo- 
hyoid  muscles.  In  some  ulcerations  of  the  epiglottis  cartilage  which 
I have  had  an  opportunity  of  seeing;  the  upper  circular  portion  which 
projects  above  the  root  of  the  tongue,  has  been  lost ; if  the  accident 
be  confined  to  that  extent  only,  deglutition  is  not  impaired,  because 
still  enough  of  the  epiglottis  is  left  to  perform  the  office  assigned  to  it, 
as  the  upper  part  is  less  essential.  The  cases  of  its  reputed  loss  by 
wounds,  must  be  considered  as  applying  themselves  to  this  upper 
portion  only,  because  a wound  low  enough  to  remove  the  whole 
body,  would  cause  such  a destruction  of  the  rima  glottidis,  as  to  pro- 
duce an  embarrassment  of  respiration,  incompatible  wffth  life. 

It  is  probable  that  the  inferior  constrictors  of  the  pharynx,  as  well 
as  the  stylo-pharnygeal  muscles,  assist  in  this  use  of  the  thyreo- 
hyoidei. 

There  is  a well-marked  difference  in  the  larynx  of  the  two  sexes. 
In  tire  female,  it  is  generally  smaller  by  one-third  than  it  is  in  the 
male ; the  thyroid  cartilage  is  also  less  prominent,  in  consequence  of 
its  two  halves  uniting  at  an  angle  more  obtuse  the  pomum  Adami  is  ; 
therefore,  seldom  conspicuous.  The  rima  glottidis  is  also  smaller  in 


women. 


THE  TRACHEA. 


161 


The  nerves  of  the  larynx  come  principally  from  the  superior  and 
and  the  inferior  laryngeal  branches  of  the  par  vagum. 


CHAPTER  II. 

Of  the  Trachea,  and  the  Glands  bordering  upon  it. 

SECT.  I. — THE  TRACHEA.  AND  BRONCHIA.* 

The  Trachea,  or  Aspera  Arteria,  is  a cylindrical  canal  of  four  or 
five  inches  in  length  and  about  nine  lines  in  diameter,  communica- 
ting with  the  lungs  for  the  transmission  of  air.  It  opens  into  the 
larynx  above,  by  being  attached  to  the  inferior  margin  of  the  cricoid 
cartilage,  and  terminates  in  the  thorax,  opposite  the  third  dorsal 
vertebra,  by  two  ramifications  called  Bronchia.  In  this  course  it  is 
situated  over  the  middle  line  of  the  neck,  beneath  the  sterno-thyroid 
muscles,  and  separated  from  them  by  the  deep-seated  fascia  of  the 
neck  and  the  adipose  matter  beneath  it.  It  is  placed  in  front  of  the 
oesophagus,  between  the  primitive  carotid  arteries  and  the  internal 
jugular  veins.  When  it  has  got  into  the  thorax,  it  inclines  slightly  to 
the  right  side  as  it  passes  behind  the  curvature  of  the  aorta.  Of  its 
two  branches,  the  right  bronchus  is  larger  than  the  other ; it  is  also 
less  slanting,  and  an  inch  long  before  it  divides  ; it  sinks  below  the 
right  pulmonary  artery,  to  penetrate  the  lung  about  the  fourth  dorsal 
vertebra.  The  left  bronchus  being  an  inch  longer  sinks  into  the 
lung  of  the  left  side,  below  the  corresponding  pulmonary  artery,  and 
opposite  the  fifth  dorsal  vertebra.  The  bronchia  then  divide  and 
subdivide  very  minutely  through  the  lungs. 

Very  dissimilar  structures  enter  into  the  composition  of  the 
trachea;  they  are  cartilage,  ligamentous  fibre,  muscle  and  a mucous 
membrane. 


Vol.  II.— 15 


* Anat.  Atlas,  Figs.  429,  430. 


132 


ORGANS  OF  RESPIRATION. 


The  Cartilage  preserves  the  cylindrical  shape  of  the  trachea,  and 
■consists  in  from  sixteen  to  twenty  distinct  rings,  which  are  deficient 
in  the  posterior  third  of  their  circumference.  Each  ring  is  about 
twTo  lines  broad,  and  half  a line  thick,  and  is  kept  apart  from  the  one 
above  and  below  it  by  a small  interstice : sometimes,  however,  they 
run  into  each  other. 

There  is  an  almost  uniform  similitude  between  these  rings  ; the 
principal  departure  from  which  is  observed  in  the  first  being  rather 
broader  in  front  than  the  others,  and  in  the  last  ring,  which,  by  its 
corset-like  shape  in  front,  contributes,  to  the  beginning  of  each 
bronchus. 

The  rings  of  the  Bronchia,  are  like  those  of  the  trachea,  deficient 
in  their  posterior  third,  and  the  same  arrangement  holds  during 
their  primitive  ramifications  in  the  lungs.  But  as  they  subdivide 
more  and  more,  the  cartilages  do  not  succeed  each  other  so  closely, 
and  are  smaller  segments  of  circles  ; they  are  also  not  regularly  de- 
ficient at  the  posterior  third  ; but  in  place  of  the  latter,  the  bronchial 
ramification  is  furnished  with  cartilage,  consisting  in  several  pieces 
put  end  to  end.  The  pieces  become,  afterwards,  more  and  more 
scattered  and  smaller,  till  they  finally  disappear,  and  the  bronchus 
is  simply  membranous.  At  the  orifice  of  each  branch  of  the  bron- 
chia, there  is  a semi-lunar  cartilage,  forming  rather  more  than  one 
half  of  its  circumference,  and  having  its  concave  edge  upwards : 
the  whole  arrangement  resembles  somewhat  the  pasteboard  to  an 
eared  bonnet,  and  is  evidently  to  keep  the  orifice  open. 

The  Ligamentous  Structure  of  the  trachea  and  of  the  bronchia  is 
very  evident  between  the  proximate  margins  of  the  cartilaginous 
rings,  and  fills  up  the  intervals  between  them  so  as  to  make  the  tube 
perfect.  This  tissue  may  be  traced  over  the  surfaces  of  the  rings, 
forming  their  perichondrium,  so  that  they  may  be  considered  as  im- 
bedded in  it.  It  does  not  exist  in  the  same  state,  in  the  human  sub- 
ject, in  the  interval  behind ; where  a third  of  the  ring  is  defective, 
its  place  being  supplied  by  a condensed  cellular  substance  approach- 
ing to  a fibrous  character  and  intertexture ; but  in  the  bullock  it  is 
there  also.  In  the  smaller  ramifications  of  the  bronchia,  where  the 
several  little  cartilaginous  segments,  are  interposed  around  it ; it  is 
probable  that  this  tissue  contributes  to  the  whole  periphery  of  the 
ramification. 

This  ligamentous  structure  possesses  great  elasticity,  which  is 


THE  TRACHEA. 


163 


manifested  by  the  rapid  shortening  of  the  trachea,  when  its  two  ex- 
tremities are  stretched  apart  and  then  suddenly  let  loose.  And  it  is 
the  continuance  of  this  quality  of  elasticity,  in  the  minute  ramifica- 
tions of  the  bronchia,  which  proves  the  existence  of  this  tissue  there, 
even  when  it  cannot  be  very  distinctly  seen. 

The  Muscular  Structure  of  the  trachea  exists  at  the  cartilaginous 
deficiency  in  its  posterior  third,  and  consists  in  a thin  muscular 
plane  whose  fibres  pass  transversely  between  the  interrupted  ex- 
tremities of  its  cartilaginous  rings.  These  transverse  fibres  begin  at 
the  first  ring,  and  exist  all  the  way  down : they  arise  from  the  in- 
ternal faces  of  the  rings,  and  the  intermediate  elastic  ligamentous 
tissue  ; about  a line  beyond  their  extremities.  Anteriorly,  they  are 
covered  by  the  lining  membrane  of  the  trachea,  and  posteriorly,  by 
the  dense  cellular  tissue  just  spoken  of. 

A similar  arrangement  of  muscular  structure  occurs  in  the  bron- 
chia and  for  some  distance  into  the  lungs.  Where  the  cartilages 
become  scattered  and  irregular,  the  muscular  fibres  are  said,  by 
J.  F.  Meckel,  and  by  M.  Reisseissen,*  to  perform  the  whole  circuit 
of  the  bronchial  ramification,  and  to  be  visible  even  beyond  the 
existence  of  the  cartilaginous  pieces.  Soemmering  expresses  a doubt 
of  this  arrangement.!  It  is  very  difficult  in  such  minute  structure  to 
arrive  at  a satisfactory  conclusion;  careful  observations,  latterly  made, 
have,  however,  induced  me  to  adopt  the  same  conviction  as  Reis- 
seissen. Longitudinal  muscular  fibres  are  said  by  Portal  to  exist 
between  the  contiguous  margins  of  the  cartilaginous  rings,  but  the 
fact  is  far  from  being  ascertained.^ 

In  some  subjects  a very  strong  plane  of  longitudinal  muscular 
fibres,  is  seen  going  the  whole  length  of  the  trachea  on  its  posterior 
face  : being  placed  just  behind  the  transverse  muscular  fibres. 

* De  Fabrica  Pulmonis.  Berlin,  1822.  M.  Laennec  says  (Traite,  de  l’Aus- 
cultation,  Paris,  1826,  vol.  ii.  p.  189,)  that  he  has  sought  in  vain  to  verify 
these  observations  of  Reisseissen,  but  that  the  manifest  existence  of  circular 
fibres  upon  branches  of  a middling  size  and  the  phenomena  of  many  kinds 
of  asthma,  induce  him  to  view,  as  a thing  well  established,  the  temporary  oc- 
clusion of  the  small  bronchial  ramifications,  by  a spasmodic  contraction  of 
their  parietes. 

f Extimffi  autem  vel  postica;  ejus  fibrae  per  longitudinem,  a cartilagine  crB 
coidea  ad  pulmones  usque  descendunt  ac,  vel  in  ipsis  tracheae  ramis  haud 
parum  conspicui  sunt. — De  Corp.  Hum.  Fabrica. 

! Anat.  Med. 


164 


ORGANS  OF  RESPIRATION. 


The  use  of  the  muscular  tissue  has  been  pointed  out,  by  the  late 
Dr.  Physick,  as  follows: — “In  expectoration,  it  diminishes  the 
caliber  of  the  air  tubes,  so  that  the  air  having  to  pass  out  with  in- 
creased rapidity  through  them,  its  momentum  will  bring  up  the  in- 
spissated fluid  which  may  be  in  its  way.”  This  very  ingenious 
theory  has  subsequently  been  advanced  by  M.  Cruveilhier,  of  Paris, 
possibly  without  a knowledge  of  his  having  been  anticipated ; but 
certainly  not  without  the  claims  of  the  eminent  individual  to  whom 
we  owe  it,  having  been  established  by  its  publication.* 

The  mucous  Membrane  of  the  trachea  lines  its  whole  interior 
periphery,  from  the  larynx  to  the  bronchia,  and  is  continued,  under 
the  same  circumstances,  through  the  latter  to  their  minute  divisions. 
It  adheres  very  closely  to  the  contiguous  structure,  and  is  continued 
in  the  substance  of  the  lungs,  beyond  the  traces  of  any  of  the  other 
tissues  which  compose  the  bronchia ; it  indeed  terminates  in  the  air 
cells.  It  is  very  vascular,  like  other  mucous  membranes:  and  also, 
like  them,  the  venous  appears  to  prevail  over  the  arterial  vascularity. 
A successful  minute  injection  makes  it  look  as  if  it  consisted  of  a 
tissue  of  blood  vessels : thin  and  red,  it  presents  an  abundance  of 
slightly  elevated  longitudinal  folds  : one  of  the  latter,  conspicuous 
for  its  greater  size,  exists  at  the  commencement  of  the  left  bronchus, 
and  is  yet  more  developed  in  the  still-born  infant. 

The  exterior  circumference  of  the  mucous  membrane  is  studded 
with  Muciparous  Glands,  about  the  size  of  millet  seed.  These 
glands  are  particularly  conspicuous  and  abundant  on  the  posterior 
part  of  the  trachea  and  of  the  bronchia,  where  the  deficiency  of  the 
cartilaginous  rings  is  supplied  by  the  musculo  membranous  structure 
only ; and  more  of  them  exist  at  the  lower  part  of  the  trachea  and 
upon  the  roots  of  the  bronchia  than  elsewhere.  They  are  placed 
behind  the  muscular  layer,  which  their  excretory  ducts  have  to 
penetrate.  Besides  occupying  these  situations,  they  are  found  in  the 
interstices  between  the  cartilaginous  rings,  but  here  they  are  much 
smaller.  The  mucous  membrane  abounds  so  much  in  the  orifices 
made  by  their  excretory  ducts,  that  it  looks  cribriform,  wdiich  ap- 
pearance is  increased  by  floating  it  in  water. 

About  the  origins  of  the  bronchia,  there  is  a considerable  num- 
ber of  black  coloured  lymphatic  glands,  called  bronchial,  which  it 

* Wistar’s  Anatomy,  3d  edition,  vol.  ii.  p.  64  Phil.  1821. 


THE  THYHOID  GLAND. 


165 


» 

is  easy  to  distinguish  from  the  preceding  by  their  colour  and  much, 
greater  size. 

There  are  two  more  glands  of  a different  character,  which,  though 
they  do  not  enter  into  the  composition  of  the  trachea,  yet  from  their 
locality,  are  most  conveniently  studied  at  this  time : they  are  the 
Thyroid  and  the  Thymus. 


SECT.  II. — OF  THE  THYROID  GLAND.  ^ 

The  Thyroid  Gland  ( Glandula  Thyroidea ) is  placed  on  the  first- 
and  second  rings  of  the  trachea,  and  on  the  sides  of  the  larynx. 

It  consists  in  a- middle  portion  which  is  thin,  of  variable  magni- 
tude in  different  individuals,  sometimes,  entirely  wanting,  and  which, 
being  stretched  across  the  upper  part  of  the  trachea  just  belowr  the 
larynx,  is  called  its  isthmus:  and  of  two  lobes,  one  on  each  side, 
which,  being  flattened'  and-  ovoidal,  are  extended  considerably  up- 
wards  on  the  side  of  the  larynx,  and  downwards  on  the  side  of  the 
trachea  and  of  the  oesophagus.  Frequently  from  the  superior  part 
of  the  isthmus,  and  most  commonly  on  its  left  side,  a small  pyramidal 
process  runs  upwards  in  front  of  the  cricoid  and  of  the  thyroid  car- 
tilage, and  is  attached*  by  ligamentous  fibres  to  the  os  hyoides ; this 
process,  however,  varies  much  in- size  and  length  ; I have  never  seen 
it  double.  According-  to  Morgagni  and  Meckel,. the  existence  of 
this  process  is  much  more  common  than  its  absence,  which  corresr 
ponds  with  my  own  observations.  The  thyroid  gland,  when  exr- 
tended,  measures  about  three  inches  from. side  to  side. 

It  is  covered  in  front  by  the  sterno-hyoid  and  thyoid-  muscles*, 
and  laterally  by  the  omo-hyoid  and-the  sterno-mastoid.  Embracing 
the  trachea  and  the  sides  of  the  larynx,  its  lobes  repose  upon  the 
primitive  carotids,  and  the  internal  jugular  veins. 

The  thyroid  gland  has  a capsule  which  is  not  very  easily  raised 
up,  but  serves  to  give  it  a polish ; it  is  also  invested  by  the  condensed 
cellular  membrane  of  the  part  called  fascia  profunda  colli.  Its 
surface  is  smooth  and  uniform.  It  is  of  a dark  brown  colour.  When 
cut  into  or  torn,  it  is  seen  to  consist  of  several  lobules  adhering  tg , 


* Anat.  Atlas.  Fig*  ,4,1th 

15* 


166 


ORGANS  OF  RESPIRATION. 


each  other  ; but  this  arrangement  is  not  very  distinct,  except  in  an 
enlarged  or  diseased  state  ; and  may  be  traced  most  easily  by  follow- 
ing the  course  of  the  large  blood  vessels,  which  pass  in  the  inter- 
stices between  the  lobules.  The  latter  contain  many  small  vesicles, 
or  cells  filled  with  a transparent  or  yellowish  and  somewhat  unctuous 
fluid  : the  cells  are  frequently  in  a collapsed  state,  which  prevents 
them  from  being  manifest  to  the  naked  eye.  According  to  the  ob- 
servations of  Mr.  Simon,*  these  vesicles  are  completely  closed,  being 
formed  by  a delicate  homogeneous  membrane,  invested  by  a close 
capillary  network.  Intermixed  with  their  contained  fluid  are  cyto- 
blasts  which  float  freely  about,  in  it.  These  are  found  frequently 
as  the  nuclei,  of  cells  of  the  diameter  of  1-1400  of  an  inch. 

There  are  four  considerable  arteries  which  supply  this  body,  two 
on  each  side,  one  coming  from  the  external  carotid  and  the  other 
from  the  subclavian.  The  veins  follow  the  course  of  the  arteries 
for  the  most  part.  Bichat  has  made  a very  interesting  remark  on 
the  subject  of  its  blood  vessels;  that,  notwithstanding  their  size  and 
number,  and  minute  ramifications  in  it,  much  less  blood  remains  in 
its  capillary  system,  than  in  that  of  the  liver  or  kidney,  as  is  proved 
by  the  quantity  of  water  it  tinges  in  maceration  ; he,  therefore,  infers 
that  the  capillary  system  is  less  abundant. 

Anatomists  have  sought  in  vain  for  one>  or  more  excretory  ducts 
to  this  body,  and  some  have  imagined  that  they  had  found  them  ter- 
minating in  the  trachea,  or  in  the  larynx.  Santorini  considered  the 
pyramidal'  process  from  the  isthmus  as  the  desired  duct.  The  em- 
physema with  which  the  gland  has  sometimes  been  affected,  was 
supposed  to  be  a proof  of  its  communicating  with  the  trachea  by  ex- 
cretory tubes  : but  it  is  more  probable  that  the  air  was  forced  into 
the  cellular  substance,  uniting  its  lobules,  and  not  into  the  structure 
itself  of  the  gland. 

The  settled  opinion  now  seems  to  be,  that  whatever  fluid  it  secre- 
tes is  conveyed  away  by  the  lymphatic  vessels.  Meckel  has  sugges- 
ted, that  as  this  gland  is  more  voluminous  proportionately  in  early 
infancy,  particularly  its  pyramidal  process,  possibly  the  duct  may 
be  obliterated  when  the  gland  begins  to  be  restrained  in  its  growth ; 
but,  if  this  were  the  case,  the  duct  ought  to  have  been  found  during 
the  period  indicated.  The  probability  is,  that  it  is  a diverticulum 
pf  blood  from  the  salivary  glands  during  the  intermittence  of  their 


* Phil.  Trans.  1844. 


THE  THYMUS  GLAND. 


167 


action  ; and  from  the  marked  sympathy  between  it  and  the  brain  in 
goitre,  it  may  exercise  a corresponding  function  on  this  organ  during 
its  intervals  of  repose. 

Duverney*  has  described  a small  azygous  muscle  on  the  middle 
line  of  the  body,  coming  from  the  under  margin  of  the  base  of  the 
os  hyoides,  and  running  over  the  middle  of  the  thyroid  cartilage,  to 
be  insertedlnto  the  upper  margin  of  the  isthmus  of  the  thyroid  gland. 
Soemmering  calls  it  Levator  Glandulae  Thyroideae,  and  speaks  of  it 
as  being  found  more  frequently  on  the  left  side,  and  about  half  of  the 
breadth  of  the  thyreo-hyoideus.  After  many  special  examinations 
for  it  I have  found  it  in  but  few  instances;  I,  therefore,  consider  it 
rare  ; though  without  a close  attention  to  structure,  the  pyramidal 
process  of  the  isthmus  of  the  gland  may,  from  the  similitude  of  colour 
and  position,  be  very  readily  mistaken  for  it,  which  I have  reason  to 
believe  has  been  frequently  the  case.f  Some  few  fibres  are  often 
found  going  to  the  isthmus  of  the  gland  from  the  crico-thyroid,  and 
the  thyreo-hyoid  muscles,  or  from  the  thyroid  cartilage. 

SECT.  III. — OF  THE  THYMUS  GLAND  J 

This  body  ( Glandules.  Thymus ) is  placed  between  the  trachea  and 
the  upper  extremity  of  the  sternum.  It  is  irregularly  triangular,  its 
broadest  part  being  above,  and  the  narrower  below.  In  the  adult, 
it  is  in  a collapsed  and  shrivelled  state,  and  scarcely  presents  a ves- 
tige of  what  it  once  was ; it  is,  therefore,  only  in  the  infant  that  it 
can  be  satisfactorily  studied. 

At  birth,  it  is  much  larger,  not  relatively,  but  actually,  than  it  is 
in  the  adult,  and  extends  from  the  body  of  the  heart  up  to  the  thy- 
roid gland.  It  is  of  a very  soft  consistence  and  of  a pink  colour. 
It  is  surrounded  by  a capsule  of  cellular  substance,  which,  when  re- 
moved, permits  the  gland  to  be  resolved  into  two  lobes,  one  on 
either  side,  which  adhere  to  each  other.  These  lobes  may  be  sepa- 

* Essai  D’Anatomie  en  tableux  imprimes,  pi.  IV.  Paris,  1745. 

f The  unassisted  eye,  in  a strong-  light,  is  generally  sufficient  to  determine 
the  structure  ; but  in  case  of  doubt,  by  boiling  the  gland,  if  there  be  muscular 
fibres  along  this  process,  their  longitudinal  and  parallel  direction  will  become 
evident;  they  also  may  then  he  torn  asunder,  so  as  to  be  made  still  more  dis- 
tinct; whereas,  the  vesicular  structure  of  the  gland  is  not  susceptible  of  divi- 
sion into  fibres. 

% Anat.  Atlas,  Fig.  426. 


168 


ORGANS  OF  RESPIRATION. 


rated  with  facility  into  lobules,  which  contain  a whitish  cream-like 
fluid. 

A good  Essay  on  the  structure  of  this  gland,  has  been  published 
by  the  distinguished  British  surgeon  and  anatomist,  the  late  Sir 
Astley  Cooper,*  illustrated  by  excellent  plates.  From  this  it  ap- 
pears that  the  lobules  of  tbe  gland  are  formed  of  vesicles  of  various 
sizes,  discharging  into  pouches  at  the  base  of  the  lobules,  and  they 
again  discharge  into  a duct  or  common  reservoir,  which  runs  from  one 
end  of  the  gland  to  the  other,  the  consistence  of  which  duct  is  extreme- 
ly feeble.  This  duct,  the  pouches,  and  the  vesicles,  may  be  filled  with 
an  injection,  by  means  of  a pipe  introduced  into  the  substance  of  the 
gland.  A large  lymphatic  trunk  passes  from  the  gland,  on  each  side, 
into  the  transverse  vein  near  its  junction  with  vena  innominata  of  the 
right  side  or  at  the  junction  itself. 

The  observations  of  Sir  Astley  Cooper,  have  been  confirmed  in 
their  main  features,  by  those  within  two  or  three- years  past  of  Dr, 
Oesterlin  of  Jena,  and  of  Mr.  Simon  of  London,  who  also  assert  that 
the  c.ream-like  fluid  of  the  vesicles  is  mixed  with  a multitude  of  cor- 
puscles, having  the  structure  and  relations  of  nuclei.  Many  of  the 
corpuscles  are  circular,  but  others  are  flat  and  disk-like.  Their  ave- 
rage diameter  is  about  the  1-3839  of  an  inch,  and  they  are  charac- 
teristically dotted  with  from  two  to  five  very  small  dark  spots,  which 
are  either  collected  or  dispersed. f 

Sir  Astley  thinks,  or,  rather,  asks,  whether  this  gland  does  not 
prepare  a fluid  for  fetal  nourishment,  in  the  absence  of  proper  chyli- 
fication,  during  fetal  life  ? inasmuch  as  all  the  elements  of  the  blood 
are  upon  chemical  analysis,  found  in  the  fluid  contained  in  its  cavi- 
ties. 

It  is  visible  in  the  third  month  of  gestation,  and  continues  to  grow 
till  the  end  of  the  second  year  of  extra-uterine  life.  It  then  collapses, 
and  its  structure  is  effaced  about  the  twelfth  year ; its  remains  are 
scarcely  distinguishable  subsequently  from  the  surrounding  cellular 
substance.  It  is  stated  by  KrauseJ  that  in  almost  all  individuals  of 
from  twenty  to  thirty  years-  of  age,  in  whom  he  has  examined  the  con- 
dition of  this  gland,  it  was  still  existing,  and  in  some  instances,  larger 
than  in  children  ; and  that  in  persons  of  from  thirty  to  fifty  years  he 
had  found  it  of  considerable  size.  It  has  latterly  happened  to  me  to 

* London,  1832. 

j-  Br.  and  For.  Med.  Review.  April,  184G. 

j:  Muller’s  Physiology,  p.  622. 


THE  LUNGS. 


169 


see  it  in  two  persons  of  from  twenty  to  thirty  years  old,  forming  an 
oblono-  oval  body,  two  inches  or  more  long  by  twelve  or  fifteen  lines 
wide,  and  preserving  its  characteristic  structure  and  division  into 
lobes  and  lobules.  No  excretory  duct  has  been  found  for  it,  unless 
we  may  consider  as  such  the  lymphatic  trunk  alluded  to  by  Sir 
Astley  Cooper.  Though  it  clearly  belongs  to  foetal  and  infantile 
existence,  its  use  is  problematical.  The  probability  is,  that  it  is  a 
diverticulum  of  blood  from  the  lungs  during  their  state  of  quiescence 
in  foetal  life,  and  until  their  structure  becomes  confirmed  and  propor- 
tionately evolved. 


CHAPTER  III. 

Of  the  Lungs.* 

The  Lungs  ( Pulmones ) are  the  essential  seat  of  the  process  of 
respiration,  and  occupy  the  greater  part  of  the  cavity  of  the  thorax, 
as  formed  by  the  ribs  and  the  intercostal  muscles  on  the  sides ; by 
the  sternum  and  its  cartilages  in  front,  by  the  dorsal  vertebra:  behind, 
and  by  the  diaphragm  below.  They  are  two  bodies,  placed  one  on 
either  side  of  the  thorax,  and  separated  from  each  other  by  the  heart 
and  its  great  vessels.  As  the  heart  is  the  only  organ  of  much  volume 
which  is  also  included  in  the  cavity  of  the  thorax,  the  size  of  the 
lungs  is  in  a direct  relation  with  the  capacity  of  the  latter ; and  may, 
therefore,  be  known  by  external  indications  in  the  living  body.  It 
is  probable  that  there  is  no  void,  or  only  a very  small  one,  betw-een 
the  sides  of  the  lungs  and  the  sides  of  the  thorax. 

Each  lung  forms  an  irregular  cone,  the  apex  of  which  is  above, 
and  the  base  below ; the  latter,  from  resting  upon  the  diaphragm,  is 
consequently,  oblique  from  before  backwards  and  dowmwards,  and 
is  also  concave.  The  surface  which  reposes  against  the  periphery 
of  the  side  of  the  thorax,  is,  uniformly,  rounded ; but  that  which 
looks  towards  its  fellow,  is  concave,  from  being  pressed  in  by  the 
heart.  The  vertical  diameter  of  the  lung  behind,  when  it  is  fully 
distended,  goes  from  the  head  of  the  first  to  that  of  the  last  rib,  and 
is,  from  the  oblique  direction  of  the  diaphragm,  consequently,  much 


* Anat.  Atlas,  Fig.  427. 


170 


ORGANS  OF  RESPIRATION. 


more  considerable  than  the  vertical  diameter  in  front,  which  extends 
only  from  the  first  rib  to  the  inferior  end  of  the  second  bone  of  the 
sternum,  or,  in  other  words,  to  a level  with  the  tendinous  centre  of 
the  diaphragm. 

The  lungs  of  the  adult  are  of  a light  pink  colour,  with  specks  or 
patches  of  black ; in  early  life  there  is  much  less  of  the  latter,  and 
in  advanced  life  it  becomes  more  abundant. 

The  left  lung  is  divided  into  two  lobes  by  a deep  fissure,  which 
begins  behind,  on  a level  with  the  fourth  dorsal  vertebra,  and  runs 
obliquely  downwards  and  forwards  to  the  anterior  margin  of  its  base. 
A deep  fissure  in  a nearly  similar  situation  is  observed  on  the  right 
lung ; but  from  it  another  fissure  branches  out  forwards,  by  which 
the  right  lung  is  divided  into  three  lobes.  The  internal  face  of  the 
left  lung  is  also  rather  more  concave  than  that  of  the  right,  from  the 
side  of  the  heart  projecting  into  it.  The  right  lung  is  more  volumi- 
nous than  the  left,  which  corresponds  with  the  greater  size  of  the 
bronchus  on  this  side,  but  its  vertical  diameter  is  not  so  great,  owing 
to  the  pressure  of  the  liver  from  below ; though  this  diameter  is  in- 
creased by  the  descent  of  the  liver  when  we  are  upright. 

Near  the  middle  of  the  internal  face  of  each  lung  are  to  be  seen 
the  points  of  connexion  with  the  bronchus,  and  with  the  pulmonary 
vessels.  Before  these  the  anterior  margin  is  thin,  and  more  or  less 
winding  where  the  lung  is  introduced  between  the  heart  and  the  front 
parietes  of  the  thorax.  When  the  lungs  are  fully  inflated,  only  a 
very  small  portion  of  the  front  of  the  pericardium  can  be  seen  be^ 
tween  them.  The  posterior  margin  is  thick,  and  rounded  where  it 
rests  against  the  vertebral  column. 

The  whole  rounded  circumference  of  the  lung  as  well  as  its  base, 
though  they  are  in  contact  with  the  parietes  of  the  thorax,  do  not 
adhere  at  any  point  to  them.  The  connexion  of  the  lung,  constitu- 
ting its  Root,  as  it  is  called,  and  by  which  it  is  maintained  in  its 
situation,  is  entirely  on  the  side  of  its  concave  face,  where  the  pul- 
monary vessels  and  bronchus  enter,  and  though  other  attachments 
are  frequently  found  springing  from  different  points  of  the  thorax, 
they  are  purely  the  results  of  disease. 


Of  the  Texture  of  the  Lungs. 

Each  lobe  of  the  lungs  is  divided  into  a great  many  distinct  lo- 
bules, which  adhere  together  by  intermediate  cellular  tissue.  The 


THE  LUNGS. 


171 


marks  of  these  divisions  are  apparent  on  the  surface  by  lines  run- 
ning in  different  directions,  but  they  are  made  still  more  distinct  by 
tearing  them  asunder.  The  Lobules  are  sub-divided  into  very  fine 
air  vesicles  or  cells,  which  maybe  considered  as  the  dilated  termina- 
tions of  the  ultimate  branches  of  the  bronchia,  with  the  same  struc- 
ture of  an  elastic  and  of  a mucous  membrane.  The  opinion  is  gener- 
ally held,  that  the  cells  do  not  communicate  laterally  with  one  another 
as  the  cells  of  the  bones,  but  only  with  the  ramifications  of  the  bron- 
chia, to  which  they  respectively  belong.  Numerous  observations 
however,  have  induced  me  to  abandon  this  idea,  and  to  conclude 
that  the  cells  of  the  lobules  individually  communicate,  but  not  those 
of  different  lobules.  I have  succeeded  in  proving  this  by  distending 
the  air  cells  with  tallow,  and,  after  the  lung  was  dried,  removing 
the  tallow  with  spirits  of  turpentine.  This  process  shows  the  cells 
of  their  natural  size,  and  communicating  freely.  A very  small  por- 
tion of  a lung  of  either  the  human  subject  or  the  calf  kept  inflated 
and  dried  shows  the  same  unequivocally.* * * § 

The  most  prevalent  opinion,  however,  of  the  day  is  that  derived 
from  Willis  originally,  that  the  air  vesicles  have  the  same  relation  to 
the  bronchioles,  that  the  berries  have  to  the  stem  in  a bunch  of 
grapes.  This  idea  has  been  reiterated  by  Reisseissen,f  and  his 
plates  fallaciously  taken  as  the  standard  of  structure,  in  the  anato- 
mical works  generally.  It  has  also  been  reasserted  still  more  lately, 
by  Huschke  under  the  declaration  of  the  opposite  being  the  repro- 
duction of  an  ancient  error,  f On  the  contrary,  my  opinion,  sus- 
tained by  numerous  anatomical  preparations,  may  be  traced  as  far  back 
as  Helvetius  and  Duverney,  and  has  as  its  advocates  Haller,  Soemmer- 
ing, J.  F.  Meckel,  and  Cruveilhier.  The  doctrine  is  moreover  de- 
cidedly advocated  with  some  modified  views,  in  regard  to  the  shape 
of  the  cells,  by  J.  M.  Bougery,  an  anatomist  now  well  known  for 
his  splendid  anatomical  plates.  The  leading  peculiarity  of  his  views, 
is  that  the  cells,  though  they  communicate  freely,  are  yet  canalicular,  § 
that  is,  they  have  the  measurement  of  length  exhibiting  great  excess 
over  every  other,  in  which  I do  not  agree  with  him. 

In  tracing  the  terminations  of  the  bronchia,  in  the  substance  of  the 
lungs,  the  parietes  of  these  canals  are  observed  to  become  very  thin, 

* Anat.  Atlas.  Fig.  427.  from  preparation  in  Anat.  Museum. 

f De  Pulmon.  Struct.  1803. 

f:  Traite  de  Splanch.  p.  249.  Paris,  1845. 

§ Gazette  Med.  de  Paris.  July,  1842. 


172 


ORGANS  OF  RESPIRATION. 


and  especially  after  the  cartilaginous  structure  has  ceased.  The  ra- 
mifications or  bronchioles  seem  then  to  be  composed  almost  entire!) 
of  a filamentous  coat,  lined  with  a delicate  mucous  membrane. 

The  filamentous  coat,  is  no  doubt  an  extension  of  the  membra- 
nous portion  existing  so  conspicuously  on  the  back  of  the  bronchia, 
and  it  retains  the  extensibility  and  contractility  of  the  same.  Its 
filaments  are  principally  in  a circular  direction  and  resemble  so 
strongly  muscular  fibres,  that  they  alone  seem  to  exist.  It  is,  how- 
ever more  probable,  that  exterior  to  these,  we  have  a fine  elastic 
ligamentous  layer,  or  it  may  be  blended  with  them,  it  being  difficult 
to  distinguish  where  there  is  such  a sameness  of  colour,  the  one 
tissue  from  the  other.  Some  anatomists,  have  indeed,  considered  it 
all  as  of  an  elastic  ligamentous  character,  in  which  case,  the  circu- 
larity of  the  fibres,  may  be  compared  to  the  same  condition  in  the 
internal  layer  of  the  corpus  cavernosum  penis. 

The  lining  mucous  membrane  of  the  bronchia  is  smooth,  polished, 
and  so  thin  that  it  is  a mere  film,  about  the  thickness  and  transpa- 
rency of  the  peritoneum,  where  it  covers  a small  intestine.  Longi- 
tudinal folds  may  be  traced  in  the  length  of  this  mucous  membrane 
for  some  distance  down  the  bronchia,  indeed  as  far  as  the  cartilagi- 
nous segments  of  circles  appear,  and  even  into  the  finer  branches. 
With  the  aid  of  a lens,  mucous  follicles  are  very  perceptible  in 
innumerable  cpiantities  all  over  it.  It  may  also  be  remarked,  that 
the  bronchia  do  not  end  by  a regular  succession  of  proportionately 
finer  and  finer  branches ; but  that  a bronchial  trunk,  of  some  lines 
in  diameter,  sends  off  in  different  directions  to  the  contiguous  lobules, 
branches  about  the  size  of  a bristle,  which  are  followed  with  much 
difficulty,  owing  to  their  collapsing : the  probability  is,  however, 
that  each  one  of  these  branches  belongs  to  a lobule  and  discharges 
into  its  cells,  in  a manner,' resembling  a blow-pipe  fixed  to  the  side 
of  a small  piece  of  sponge.  In  my  preparations,  these  terminating 
tubes  of  the  bronchia,  the  size  of  bristles,  are  seen  very  distinctly  ; 
but  there  is  no  appearance  of  the  penicillous  arrangement,  which  would 
be  apparent  if  each  cell  had  its  owm  specific  branch  of  the  bronchus 
running  to  it. 

The  internal  surface  of  the  lung  owing  to  this  multiplication  of  it 
by  cells,  may  be  considered  as  a vast  area  obtained  in  a very  small 
space,  and  containing  a close  intertexture  of  the  most  minute  capil- 
laries, for  the  purpose  of  exposing  the  blood  to  the  process  of  respi- 
ration. 


THE  LUNGS. 


173 


There  is  no  absolutely  uniform  size  for  the  air  vesicles,  but  their 
diameter  may  be  stated  as  from  near  the  two  hundredth  part  to  the 
fiftieth  of  an  inch.  Weber  says  from  the  T^9  to  jis-  The  capillary 
blood  vessels  have  an  extremely  attenuated  distribution  over  them; 
leaving  scarcely  any  thing  like  regular  interstice,  these  capillaries 
are  in  their  own  diameter,  about  the  twentieth  part  of  the  diameter 
of  the  smaller  air  vesicles. 

The  readiness  of  pulmonary  haemorrhage,  is  a sufficient  proof 
of  the  facility  with  which  blood  passes  from  the  blood  vessels  into 
the  air  vesicles  and  bronchial  tubes.  An  opposite  line  of  commu- 
nication from  the  air  vesicles  into  the  pulmonary  blood  vessels  has 
latterly  attracted  my  attention,  and  been  the  subject  of  several 
experiments,  which  prove  conclusively  the  certainty  of  the  fact. 
These  experiments  show  that  water  or  air  may  be  injected  into  the 
air  passages  of  the  lungs,  and  returned  by  the  pulmonary  veins,  and 
the  pulmonary  artery,  but  with  especial  freedom  through  the  pulmo- 
nary veins.*  Whether  this  is  by  an  absolutely  direct  communication, 
or  by  the  intervention  of  the  lymphatic  system  I cannot  at  present 
determine,  but  the  existing  state  of  my  experience  is  in  favour  of  the 
first.  It  may,  however  be  stated,  that  it  is  a matter  of  common  ex- 
perience with  anatomists,  to  inflate  the  pulmonary  lymphatics  from 
the  air  vesicles ; also,  to  inject  the  pulmonary  lymphatics  from  the 
bronchial  arteries,  and  therefore,  the  communication  of  the  air  vesi- 
cles with  the  blood  vessels^may  be  by  this  series  of  anastomoses ; 
that  is  going  from  the  air  vesicles  to  the  lymphatics,  and  from  them 
into  blood  vessels,  which  all  communicate  freely  with  one  another. 

Besides  the  ramifications  of  the  bronchia,  the  substance  of  the 
lungs  is  composed  of  numerous  blood  vessels  and  lymphatics,  and 
is  well  supplied  with  nerves. 

The  blood  vessels  are  of  two  kinds,  the  pulmonary  and  the  bron- 
chial. The  pulmonary  artery,  coming  from  the  right  ventricle  of  the 
heart,  divides  under  the  arch  of  the  aorta  into  two  large  branches: 
one  for  the  right  lung,  and  the  other  for  the  left.  The  right  branch 
is  larger  than  the  left.  Each  of  these  branches  having  reached  the 
upper  part  of  the  root  of  its  respective  lung,  begins  there  to  distri- 
bute itself  in  large  trunks,  which  divide  and  subdivide  throughout 
the  substance  of  the  lung.  The  terminating  branches  finally  become 
capillary,  and  ramify  in  the  parietes  of  the  air  cells,  where  the  blood 

* For  the  details  of  Experiments,  see  Am.  Journ.  Med.  Sc.  p.  332.  April, 
1843. 


1 74 


0RGAXS  OF  RESPIRATION. 


which  they  carry,  from  being  dark-coloured  and  venous,  is  so  altered 
as  to  have  the  arterial  qualities  restored  to  it,  and  to  become  of  a 
bright  red.  From  the  ultimate  branches  of  the  pulmonary  artery, 
arise  the  first  branches  of  the  pulmonary  veins.  These  are  succes- 
sively accumulated  into  two  large  trunks  on  each  side,  which,  issuing 
at  the  lower  part  of  the  root  of  the  lung,  go  to  open  into  the  left 
auricle  of  the  heart.  It  has  been  remarked  by  Mr.  Boyer,  that  the 
two  pulmonary  veins,  are  less  capacious  than  the  pulmonary  artery 
of  the  same  side,  in  which  they  manifest  a peculiarity  of  blood  ves- 
sels, differing  from  what  exists  in  other  parts  of  the  body.  The 
pulmonary  artery  and  veins  are  distributed  in  company  with  the 
bronchus.  From  the  observations  of  Professor  Mayer,  it  appears 
that  valves  exist  in  the  pulmonary  veins,  contrary  to  the  general 
opinion  of  anatomists.  They  are  found  where  smaller  trunks  join 
the  larger  ones,  at  an  acute  angle  ; but  there  are  none  where  they  join 
at  a right  angle.* 

The  second  order  of  blood  vessels,  being  the  bronchial,  also  con- 
sists in  arteries  and  in  veins,  and  are  for  the  nourishment  of  the 
lungs.  They,  too,  attend  the  branches  of  the  bronchia.  The  bron- 
chial arteries  pervade  the  substance  of  the  lung  by  innumerable  fine 
branches,  and  anastomose  with  the  pulmonary  arteries.  The  bron- 
chial veins  also  anastomose  with  the  pulmonary  veins,  but,  finally, 
come  out  in  small  trunks  from  the  root  of  the  lung;  the  right  one 
empties  into  the  vena  azygos,  and  the  left  into  the  trunk  of  the  su- 
perior intercostal  veins  of  the  left  side  about  the  third  dorsal 
vertebra. 

The  Lymphatics  of  the 
lungs  are  numerous ; after 
traversing  the  black  bron- 
chial glands,  those  of  the 
left  side  empty  into  the  tho- 


extremity. 

The  nerves  come  princi- 
pally from  the  par  vagum. 
Some  of  them  are  distributed 
with  the  bronchus,  and  may 
be  traced  easily  far  along  its 


racic  duct,  and  those  of  the 
right  into  the  large  lymphatic 
trunk  coming  from  the  upper 


Fig.  33. 


Arrangement  of  the  Capillaries  of  the  air- 
cells  of  the  Human  Lung. 


* Am.  Med.  Jour.  vol.  iii.  p-  186. 


THS  LUNGS. 


175 


branches,  forming  beautiful  anastomoses  around  them : their  texture 
there  resembles  much  that  of  the  sympathetic:  they  are  thought  to  be, 
finally,  spent  upon  the  mucous  membrane : others  seem  to  be  more 
specifically  appropriated  to  the  vessels. 

It  will  now  be  understood  that  the  root  of  each  lung  is  formed  by 
a pulmonary  artery,  two  pulmonary  veins,  and  a bronchus,  covered 
by  the  pleura,  where  the  latter  extends  from  the  lung  to  the  pericar- 
dium. The  relative  situation  is  such,  that  the  pulmonary  artery  is 
above,  the  bronchus  in  the  centre  and  behind,  and  the  pulmonary 
veins  below. 

The  texture  of  the  lung  is  so  light  and  spongy  after  an  animal  has 
once  breathed,  that  its  weight  is  very  inconsiderable  when  compared 
with  its  volume.  Its  cells  are  left  much  distended,  even  when  the 
animal  is  dead ; and,  notwithstanding  from  its  unusual  elasticity,  it 
expels  a great  quantity  of  air  when  the  thorax  is  opened,  and  is- 
thereby  reduced  to  a third  of  its  size  during  life ; yet  it  retains 
enough  air  to  make  it  float  in  water,  or  even  in  spirits  of  wine. 
The  quantity  of  air  which  the  lungs  contain  differs  very  considerably 
in  different  individuals,  depending  entirely  upon  the  capaciousness  of 
the  thorax.  Its  medium  amount  is  computed  at  one  hundred  and 
forty-five  cubic  inches,  thirty  cubic  inches  of  which  are  changed  at 
every  act  of  respiration. 


Of  the  Pleura* 

Each  lung  has  a perfect  covering  of  a serous  membrane,  called 
Pleura,  to  which  it  is  indebted  for  its  shining  surface.  This  mem- 
brane is  also  reflected  from  the  internal  surface  of  the  lung  to  the 
adjacent  side  of  the  pericardium,  and  is  then  spread  over  the  inte- 
rior periphery  of  that  half  of  the  thorax  to  which  it  belongs,  by 
lining  the  ribs  and  intercostal  muscles,  and  covering  the  convex 
face  of  the  diaphragm.  There  are,  therefore,  two  pleurae,  each  of 
■which  is  confined  to  its  appropriate  half'  of  the  thorax,  so  as  to  line 
its  cavity  and  to  cover  its  lung. 

The  pleura,  as  other  serous  membranes,  is  a thin  sac.  Its  circum- 
ference is  entire,  like  that  of  an  inflated  bladder ; there  is,  therefore, 
no  point  or  line  at  wdiich  one  may  exclusively  begin  an  account  of 


* Anat.  Atlas,  Fig.  436. 


176 


ORGANS  OF  RESPIRATION. 


its  course  and  attachments.  To  commence,  however,  at  the  ster- 
num ; the  pleura  goes  thence  outwardly  to  line  the  lateral  parietes 
of  the  thorax,  as  formed  by  the  cartilages  of  the  ribs,  the  ribs  them- 
selves, and  the  intercostal  muscles.  In  this  way  it  may  be  traced 
around  to  the  dorsal  vertebrae,  and  over  the  convex  surface  of  the 
diaphragm.  In  proceeding  along  the  first  rib,  which  is  very  oblique, 
it  forms  a sort  of  bulging  bag,  which  projects  towards  the  trachea, 
lines  the  lower  part  of  the  scalenus  anticus  muscle,  and  receives  the 
upper  extremity  of  the  lung.  The  pleura,  having  reached  the  dorsal 
vertebrae  from  the  ribs,  passes  from  their  sides  forwards  to  the  pos- 
terior part  of  the  pericardium,  a very  small  portion  of  which  it 
covers.  It  then  goes  upon  the  posterior  face  of  the  pulmonary  ves- 
sels and  of  the  bronchus  to  the  lung,  and  applies  itself  closely  to  the 
latter.  It  then  covers  the  part  of  the  lung  posterior  to  its  root,  and 
continues  to  advance  along  the  rounded  surface  of  the  lung  to  its 
anterior  margin : it  then  passes  over  the  internal  surface  of  the  lung, 
which  is  anterior  to  its  root.  It  afterwards  covers  the  front  of  the 
pulmonary  vessels  and  of  the  bronchus,  and  gets  in  a very  short 
space  to  the  pericardium.  It  then  passes  forwards  on  the  side  of 
the  latter,  and  having  got  near  its  middle  line,  goes  from  it  to  the 
sternum,  and  reaches  the  line  from  which  the  description  of  its 
course  commenced. 

There  is  no  important  difference  between  the  two  pleurae,  either 
in  their  mode  of  reflection  or  in  the  organs,  to  which  they  are  at- 
tached, so  that  the  description  of  one  will  apply  to  the  other.  The 
portion  of  each  pleura  covering  the  lung  is  called  Pleura  Pulmonalis, 
and  that  portion  which  lines  the  thorax  is  the  Pleura  Costalis  ; that 
covering  the  Diaphragm  is  the  Pleura  Diaphragmalis.  A duplica- 
ture  of  the  pleura  commences  at  the  inferior  margin  of  the  pulmo- 
nary veins,  and,  descending  as  far  as  the  diaphragm,  attaches  the 
inferior  portion  of  the  posterior  margin  of  each  lung,  to  the  side  of 
the  pericardium  in  front  of  the  vertebra.  This  duplicature  is  the 
Ligamentum  Pulmonis.  It  is  longer  on  the  left  lung  than  on  the 
right,  by  reason  of  the  greater  vertical  diameter  of  the  former. 

From  what  has  been  said  it  will  now  be  readily  understood,  that 
the  whole*  cavity  of  the  thorax  is  divided  vertically  into  two  halves, 
by  that  portion  of  the  two  pleura  which  advances  from  the  spine 
towards  the  sternum.  This  septum  is  called  the  Mediastinum,  and 
the  heart,  enveloped  by  the  pericardium,  is  placed  in  its  centre, 
and  separates  the  two  pleura  widely  apart.  It  has  been  found 


THE  LUNGS. 


177 


useful  by  anatomists,  for  descriptive  purposes,  to  subdivide  the  me- 
diastinum into  three  portions  or  regions.  One  passing  from  the 
front  of  the  pericardium  to  the  posterior  face  of  the  middle  line  of 
the  sternum,  is  the  Anterior  Mediastinum  ; another,  passing  from  the 
posterior  face  of  the  pericardium  to  the  dorsal  vertebrae,  is  the 
Posterior  Mediastinum  ; and  a third,  which  is  within  the  circuit  of 
the  first  ribs,  is  the  Superior  Mediastinum.  This  division,  though 
evidently  arbitrary,  is  indispensable  to  a correct  account  of  the 
relative  situation  of  very  important  organs  placed  between  the  two 
pleurae. 

1.  The  Anterior  Mediastinum  is  less  important  than  the  other 
two  ; the  portions  of  the  two  pleurae  of  which  it  consists  are  almost 
in  contact,  and  contain  between  them  some  loose  cellular  substance 
by  which  they  adhere  together,  and  by  cutting  through  wdiich,  after 
a longitudinal  section  of  the  sternum,  they  are  easily  separated  from 
one  another.  The  upper  part  of  this  septum  contains  the  remains 
of  the  thymus  gland;  its  lower  part  leaves  the  middle  line  of  the 
sternum,  and  inclines  to  the  left  side;  and  when  the  sternum,  is- 
narrow  below,  it  is  attached  to  the  anterior  ends  of  the  cartilages  of 
the  lower  true  ribs  of  that  side. 

2.  The  Posterior  Mediastinum,  where  it  leaves  the  vertebra  to 
reach  the  pericardium,  passes  off  from  a line  nearer,  the  heads  of  the 
ribs  on  the  left  side,  than  on  the  right.  The  descending  portion  of 
the  thoracic  aorta  is  contained  within  this  septum,  on  the  left  side  of 
the  dorsal  vertebra.  The  oesophagus  is  in  its  middle  in  front  of  the 
vertebrae  above,  but,  in  descending  it  crosses-  in  front  of  the  aorta, 
and  inclines  to  the  left  side  of  the  dorsal  vertebra  to  reach  the  fora- 
men cesophageum  of  the  diaphragm.  The  vena  azygos  occupies 
the  right  side  of  this  mediastinum,  and,  after  ascending,  forms  an 
arch  over  the  root  of  the  right  lung,  and  terminates  by  joining  the 
descending  cava.  The  thoracic  duct,  after  entering  the  thorax  be- 
tween the  crura  of  the  diaphragm,  ascends  in  front  of  the  dorsal  ver- 
tebra between  the  aorta  and  the  vena  azygos,  and  behind  the  oeso- 
phagus, till  it  reaches  the  third  dorsal  vertebra ; it  then  inclines  to 
the  left  side,  and  mounting  into  the  root  of  the  neck  near  the  ver- 
tebra, it,  finally,  makes  an  arch,  which,  by  advancing  forwards,  ter- 
minates in  the  angle  formed  by-the  junction  of  the  left  internal  jug.u- 

16* 


ITS 


ORGANS  OF  RESPIRATION. 


lar  and  left  subclavian  vein.  The  par  vagum  nerve,  of  both  sides, 
is  also  in  the  posterior  mediastinum. 

3.  The  Superior  Mediastinum  is  bounded  in  front  by  the  upper 
part  of  the  sternum,  behind  by  the  upper  dorsal  vertebrae,  and  later- 
ally by  the  first  ribs.  The  cavity  is  conoidal,  with  the  base  upward, 
but  is  too  peculiar  to  admit  of  a rigid  comparison  with  any  thing 
else.  The  pleurae  are  reflected  downwards  from  the  internal  edge 
of  the  first  ribs,  not  abruptly,  but  in  a rounded  bulging  manner,  re- 
ceiving there,  as  mentioned,  the  tip  or  apex  of  the  lungs,  and  lining 
the  inferior  surface  of  the  scalenus  anticus  muscle.  In  order  to  un- 
derstand well  the  position  of  the  pleurae,  it  must  be  borne  in  mind 
that  the  upper  rib  is  placed  very  obliquely  downwards  and  forwards, 
at  an  angle  of  about  forty-five  degrees  with  the  spine  ; consequently, 
the  pleura,  on  being  reflected  from  its  whole  internal  edge,  is  much 
higher  at  the  head  of  the  rib  than  it  is  at  the  anterior  extremity  of 
the  same.  This  cavity  is  continuous,  of  course,  with  that  of  the 
anterior  mediastinum  in  front,  and  also  with  that  of  the  posterior 
mediastinum  behind^ 

The  remains  of  the  thymus  gland  are  where  this  cavity  joins  the 
anterior  mediastinum  : a part  of  the  gland  is,  indeed,  in  each  of  these 
cavities  just  below  the  transverse  vein.  In  contact  with  the  right 
pleura  is  the  descending  Vena  Cava.  The  common  trunk  of  the 
Left  Subclavian,  and  Internal  Jugular,  called  the  Transverse  Vein, 
or  Vena  Innominata,  after  crossing  in  an  oblique  descent  behind  the 
upper  portion  of  the  sternum,  joins  the  descending  cava  an  inch 
above  the  place  where  the  latter  penetrates  into  the  pericardium. 
Behind  the  transverse  vein  are  the  top  of  the  arch  of  the  aorta,  the 
arteria  innominata,  the  left  carotid,  and  the  left  subclavian.  The 
trachea,  with  the  oesophagus  behind  it,  descends  along  the  middle 
line  in  front  of  the  spinal  column.  The  arteria  innominata  crosses 
the  front  of  the  trachea  from  left  to  right  in  ascending;  it  is  in  contact 
with  the  transverse  vein,  and  more  superficial  than  either  of  the  other 
arteries.  The  phrenic  nerve,  passing  at  the  internal  edge  of  the 
scalenus  anticus,  between  the  subclavian  artery  and  vein,  descends 
vertically  in  contact  with  the  pleura.  The  par  vagum  passes  along 
the  side  of  the  trachea,  and  afterwards  behind  the  corresponding 
bronchus,  having  got  into  the  superior  mediastinum  between  the 
subclavian  vein  and  artery:  its  inferior  laryngeal  branch  encircles  the 


THE  LUNGS. 


179 


subclavian  artery  on  the  right  side,  and  the  arch  of  the  aorta  on  the 
left. 

The  internal  surface  of  the  pleura  is  smooth  and  polished,  and  is 
moistened  and  kept  lubricated  by  an  unctuous  serum,  the  natural 
quantity  of  which  is  merely  sufficient  to  allow  the  parts  to  slide  freely 
upon  each  other.  In  dropsy  of  the  chest,  it  is  augmented  frequently 
to  such  an  amount  as  to  cause  the  collapse  of  the  lung  by  pressing 
upon  it. 

In  the  cellular  tissue,  between  the  pleura  and  pericardium,  as  well 
as  on  the  diaphragm,  adipose  matter,  in  considerable  abundance,  is 
found  in  corpulent  persons  advanced  in  age. 

The  blood  vessels  of  the  pleura  costalis  are  derived  from  those 
which  supply  the  parietes  of  the  thorax,  as  the  intercostals  and 
phrenics.  They  ramify  in  the  subjacent  cellular  substance,  and  end 
by  exhalant  orifices  on  the  internal  face  of  the  pleura,  from  which  a 
minute  injection  is  poured  out  very  copiously. 


BOOK  VIII 


OF  THE  CIRCULATORY  SYSTEM. 

PART  I. 

HISTOLOGY  OF  THE  CIRCDLATORY  SYSTEM. 

CHAPTER  I. 

General  Considerations. 

The  Circulatory  or  the  Vascular  System,  consists  in  a congeries 
of  tubes,  or  cylindrical  canals,  which  convey  the  blood  to  and  from 
every  part  of  an  animal  body,  and  therefore,  enter  into  the  texture 
or  composition  of  almost  every  portion  of  it.  In  all  animals  there 
seems  to  be  a necessity  for  the  alternate  reception  and  discharge  of 
alimentary  materials;  in  the  higher  orders,  this  is  effected  through 
the  agency  of  the  vascular  system ; but  in  the  most  simple  animals 
this  system  does  not  exist,  and  their  whole  fabric  being  soft  and 
permeable,  nutritious  matter  is  introduced  by  a direct  absorption,  or 
a species  of  capillary  attraction,  after  the  manner  of  a sponge,  or 
any  other  porous  body,  and  is  discharged  by  a process  equally 
simple.*  It  is  probable  that  there  are  some  parts  of  the  human 
body  whose  mode  of  nutrition  is  analogous  to  the  latter;  as,  for  ex- 
ample, the  articular  cartilages,  the  hair,  nails,  and  so  on;  for  many 
observations  tend  to  prove  that  all  these  organs  have  an  interstitial 
circulation. 

* Hunter  on  the  Blood.  Bedard,  Anat.  Gen. 


1S2 


CIRCULATORY  SYSTEM. 


In  many  animals,  the  blood  is  propelled  from  a central  point, 
called  the  heart,  to  all  parts  of  the  body,  and  then  returns  again  to 
the  heart.  The  first  movement  is  executed  through  canals  called 
arteries,  and  the  second  through  veins.  It  is  the  most  simple 
scheme  by  which  a circulation  can  be  carried  on  through  a sangui- 
ferous system,  and  requires  a heart  with  only  two  cavities;  one  for 
propelling  blood  into  the  arteries,  or  departing  tubes,  and  another 
as  a reservoir  for  receiving  the  blood  of  the  returning  tubes,  or  the 
veins.  The  two  cavities  must  be  near  each  other,  and  have  a 
valvular  opening  between  them,  which  will  permit  the  blood  to 
pass  from  the  venous  into  the  arterial  reservoir;  but  not  from  the 
arterial  into  the  venous.  A circulation  of  this  simple  cast  is  found 
in  fishes,  and  in  animals  generally  whose  respiration  is  effected  on 
the  surface  of  the  body;  but  in  man,  and  in  other  warm-blooded 
animals,  where  respiration  is  carried  on  interiorly  by  means  of  the 
lungs,  their  circulatory  apparatus  is  double;  one  part  being  for  the 
lungs,  and  the  other  part  for  the  body  generally. 

In  man,  the  heart  consists  of  four  cavities;  two  auricles,  or  re- 
servoirs of  blood  from  the  veins,  and  two  ventricles,  into  which  the 
venous  blood  is  transmitted,  and  which,  in  (heir  functions,  may  be 
compared  to  the  forcing-pump  of  a fire-engine.  The  circulation  is 
effected  in  the  following  manner:  The  blood  contained  in  the  right 
auricle  of  the  heart  flows  into  the  right  ventricle,  and  from  the  latter 
it  is  forced  through  the  pulmonary  artery  into  the  lungs.  It  returns 
from  the  lungs  through  the  four  pulmonary  veins,  and  is  received 
into  the  left  auricle  of  the  heart;  from  the  latter  it  flows  into  the  left 
ventricle,  and  is  propelled  from  it  into  the  aorta.  The  aorta  then 
distributes  it  through  the  whole  body  by  an  infinitude  of  small 
branches;  from  the  latter  it  is  collected,  by  corresponding  veins, 
into  two  trunks,  the  Ascending  and  the  Descending  Vena  Cava. 
The  ascending  vena  cava  brings  the  blood  from  the  lower  extremities 
and  from  the  abdomen  ; the  descending  vena  cava  brings  the  blood 
from  the  head  and  neck,  the  upper  extremities,  and  the  parietes  of 
the  thorax.  These  two  trunks  finally  discharge  the  blood  into  the 
cavity  from  which  it  started,  to  wit,  the  right  auricle.  The  same 
round  is  then  renewed,  and  continues  to  be  repeated  during  the 
whole  course  of  life.  It  is  customary  for  anatomists  to  call  the 
route  of  blood  from  the  right  ventricle,  through  the  lungs,  to  the 
left  auricle  inclusively  the  lesser  or  the  pulmonary  circulation;  and 


GENERAL  CONSIDERATIONS. 


183 


that  which  begins  at  the  left  ventricle,  goes  through  the  whole  body, 
and  ends  in  the  right  auricle,  the  greater  circulation. 

The  blood  contained  in  the  veins  of  the  greater  circulation,  in 
the  right  auricle  and  ventricle,  and  in  the  pulmonary  artery,  is  of 
a dark  brown  or  reddish  colour;  while  that  contained  in  the  pul- 
monary veins,  in  the  left  auricle  and  ventricle,  and  in  the  aorta  and 
its  ramifications,  is  from  being  vivified  by  respiration,  of  a carmine 
or  vermillion  complexion.  The  celebrated  Bichat  has,  upon  this 
difference  of  colour,  founded  his  division  of  the  whole  circulating 
system  into  two  parts;  one  containing  black  blood,  “ System e vas- 
culaire  a sang  noire  ;”  the  other  red  blood,  “ Systeme  vasculaire  a 
sang  rouge.”  This  division  having  general  physiology  for  its  object, 
affords  a well  marked  distinction,  suited  to  such  discussions. 

The  lymphatics  also  are  a part  of  the  circulatory  system,  but  as 
they  do  not  commonly  convey  red  blood,  the  consideration  of 
them  will  be  introduced  subsequently.  “ They  take  a very  active 
part  in  the  animal  economy,  whether  natural  or  diseased,  and  seem, 
in  many  actions,  to  be  the  antagonists  of  the  arteries,  while  the  veins 
are  much  more  passive  being  principally  employed  in  returning  the 
blood  to  the  heart.”* 

The  largest  vascular  trunks  are  situated  near  the  centre  of  the 
body  and  limbs,  on  the  side  upon  which  flexion  is  accomplished, 
while  those  near  the  surface  are  generally  small.  Most  commonly 
there  are  one  artery,  one  or  two  veins,  and  several  lymphatics,  all 
together. 

The  arterial  system  in  its  external  configuration  may  be  com- 
pared to  a tree,  the  trunk  of  which  is  attached  to  the  heart,  and 
which  by  a continued  succession  of  divisions  and  subdivisions 
reaches  to  every  part  of  the  body.  There  are  no  means  of  estima- 
ting rigidly  the  collective  area  of  the  branches  in  proportion  to  that 
of  the  trunk,  but  a little  observation  on  the  size  of  the  primitive 
branches  will  satisfy  one  of  a great  excess  on  the  part  of  the  latter; 
and  as  the  rule  is  maintained  throughout,  there  must  finally  be  an 
immense  disproportion.  We  have  then  reason  to  believe,  that  if  all 
the  branches  were  assembled  into  a single  cavity  this  cavity  would 
be  somewhat  like  a cone,  the  apex  of  which  would  be  next  to  the 
heart.  The  same  rule  holds  in  regard  to  the  venous  system,  it  being 
observed,  however,  that  the  latter  has  two  trunks  connected  with  the 


* Hunter,  loc.  cit. 


184 


CIRCULATORY  SYSTEM. 


heart  instead  of  one.  The  general  rule  is,  therefore,  established 
throughout  the  vascular  system,  that  the  collective  area  of  the 
branches  is  always  greater  than  that  of  the  trunk  from  which  they 
proceed.*  By  the  same  rule  the  circulation  in  the  branch  must  be 

* I am  indebted  to  a scientific  friend,  Mr.  Erskine  Hazard,  for  the  follow- 
ing computation,  by  actual  measurement,  of  the  arteries,  from  which  it  appears 
that  in  many  of  them,  at  least,  the  area  of  the  trunks  is  greater  than  that  of  the 


branches  near  them. 

The  Left  Carotid  at  the  Aorta  is  - - - - .42 

Its  diameter  at  the  branching  is  - .43 

Increase  of  diameter  .01 

Its  square  at  the  Aorta  is  1764 


Each  Carotid  branch  measures  .28  and  the  sum  of  their  squares  is  1568 

The  difference  of  the  areas  of  the  Carotid  and  its  branches  is  12^  per  cent, 
in  favour  of  the  Carotid. 


Diameter  of  Aorta  near  the  Iliacs  - .64 

Its  square  ------  4096 

Diameter  of  Left  Iliac  -----  .40 

Its  square  -----  1600 

Diameter  of  Right  Iliac  ....  .37 

Its  square  -----  1369 

Sum  of  their  squares  - 2969 

Aorta  largest  by  nearly  38  per  cent.,  or  ...  1127 

Square  of  Right  Common  Iliac,  as  above,  ...  1369 

Ditto  External  Iliac  -----  900 

Ditto  Internal  do  - ...  - 729 

1629 

Branches  largest  by  nearly  19  per  cent.,  or  - - - 260 

Square  of  Left  Iliac  as  above,  - 1600 

Ditto  Internal  Iliac  - - - - ...  9G1 

Ditto  External  do  -----  - 900 

1861 

Branches  largest  by  above  16  per  cent.,  or  - - - 261 


GENERAL  CONSIDERATIONS. 


185 


more  languid  than  in  the  parent  trunks,  as  this  circulation  is  retarded 
both  by  additional  friction  and  by  having  to  fill  up  a larger  canal. * 


Great  Sinus  of  Valsalva  - - - - 13456 

Innominata  ------  2601 

Carotid  -------  1444 

Subclavian  ------  1024 

Aorta  beyond  -------  3600 

8669 

Sinus  greater  than  all,  by  * - - - - 4787 

or  55  per  cent. 


Comparison  of  the  areas  of  the  Iliac  Arteries,  with  that  of  the  Aorta,  half  an 


inch  above  them,  in  decimals  of  an  inch. 

Left  Iliac.  Aorta. 

Right  Iliac. 

Greatest  diameters 

.354 

.556 

.390 

Least  do 

.290 

.410 

.290 

Sum  of  diameters 

.644 

.966 

.680 

Mean  diameters 

.322 

.483 

.340. 

Their  squares 

103684 

233289 

115600 

103684 

Sum  of  the  squares 

of  the  Iliacs 

- 

219284 

Square  of  the  Aorta  - - 

- 

233289 

Aorta  larger  than  the  Iliacs  - - - 

- 

14005 

or  nearly  6 per  cent. 


As  the  areas  of  circles  are  to  each  other  as  the  squares  of  their  diameters,  it 
follows  that  the  aorta  will  contain,  in  a given  length,  nearly  6’’]4ff  per  cent., 
more  than  the  two  iliacs ; and,  consequently,  the  blood  must  flow  that  much 
faster  through  the  iliacs  than  through  the  aorta,  as  the  same  blood  has  to  be 
disposed  of  in  both,  in  the  same  time.  By  this  means  the  power  of  the  heart  is 
continued  much  farther  through  the  system,  as  each  artery  is  large  enough  to 
supply  its  branches  with  but  little  friction.  The  interior  surfaces  of  the  above 
iliacs  are,  together,  2.0806  inches,  while  that  of  the  aorta  is  but  1.518  inches, 
or  only  three-fourths  of  the  rubbing  surface!  Independently  of  this  circum- 
stance, it  is  found  that  there  is  a greater  difference  in  the  quantities  of  fluids 
passing  through  apertures  of  different  sizes  than  there  is  in  the  areas  of  the 
respective  apertures.  This  is  accounted  for  by  their  being  less  friction  between 
the  particles  of  fluids,  than  there  is  between  these  particles  and  a solid ; and, 
in  the  larger  apertures,  a smaller  proportion  of  the  particles  comes  in  contact 
with  the  solid. 

* It  is  computed  that  the  blood  moves  5233  times  slower  in  the  capillaries 
than  in  the  aorta. 

Vol.  II.— 17 


186 


CIRCULATORY  SYSTEM. 


The  course  of  rivers  exemplifies  this  continually  ; while  confined  to 
narrow  channels,  they  rush  tumultuously  through  them,  but  when 
they  begin  to  expand  themselves  into  capacious  basins,  or  to  be  di- 
vided into  a multitude  of  smaller  channels,  the  current  becomes 
slower,  and  in  some  cases  imperceptible,  though  the  fact  is  clear, 
that  an  equal  volume  of  water  is  every  where  descending  in  the 
same  period  of  time. 

The  moisture  conferred  upon  all  parts  by  the  circulation  of  the 
blood,  bears  a sufficient  analogy  to  the  effects  of  irrigation  upon 
ground.  The  w'ater  may  be  conducted  to  the  latter  by  a canal, 
and  is  finally  divided  into  an  infinitude  of  streamlets,  which  ramify 
every  where,  and  from  the  porosity  of  their  beds  percolate  laterally, 
so  that  the  whole  field,  even  to  its  most  minute  atom,  is  kept  moist- 
ened. The  streamlets,  afterwards,  successively  assemble  again  into 
a single  canal,  w'hich  bears  off  their  superabundant  waiter.  From 
the  nature  of  the  particles  of  blood,  many  of  them  are  confined  to 
their  proper  channels,  and  can  never  pass  off  by  percolation  into  the 
tissue,  through  which  the  blood  vessels  ramify.  This  may  be 
proved  by  the  fact  of  the  red  globules  of  blood  having  a diameter 
of  from  the  three-thousandth  to  the  five-thousandth  part  of  an  inch, 
a size  inconsiderable  as  it  is,  yet  too  large  to  permit  their  flowing 
through  elementary  fibres  or  atoms;  whereas  serum,  or  the  wTater  of 
the  blood,  may,  from  the  extreme  fineness  of  the  particles,  be  ab- 
sorbed by  any  tissue  whatever  ; a circumstance  entirely  unquestion- 
able, both  from  daily  observation,  as,  for  example,  in  soaking  a 
piece  of  dried  meat  or  a bone;  and  from  the  reflection,  that  the  air 
itself  will  hold  a certain  quantity  of  water  in  solution. 

A question  then  arises  whether  the  moisture  of  parts  not  supplied 
with  red  globules  of  blood,  comes  in  the  living  body  exclusively 
from  infiltration  or  from  a peculiar  set  of  vessels  called  exhalants, 
often  talked  of,  but  as  yet  never  seen?  That  the  lateral  porosities 
of  blood  vessels  are  large  enough  to  allow  watery  fluids  to  exude, 
is  readily  proved  by  injecting  water  into  the  blood  vessels  of  a 
limb,  or,  of  any  other  part,  when  the  latter  invariably  becomes  cede- 
matous.  It  is  in  this  way  even  possible  to  inundate  a living  animal, 
as  I have  seen  accomplished  by  M.  Magendie,  in  Paris.  This 
moisture  requires  a change,  and  by  continued  additions  w'ould  be- 
come superabundant : as  it  has  been  thrown  out  of  the  common  cur- 
rent of  the  circulation  and  could  not  be  removed  in  any  other  way, 
the  lymphatic  system  has,  therefore,  been  added  for  the  purpose. 


GENERAL  CONSIDERATIONS. 


187 


In  the  lower  orders  of  animals,  who  are  destitute  of  the  blood  ves- 
sels, the  interstitial  change  of  moisture  goes  on  without  lymphatics. 

No  part  of  the  human  body  is  exempt  from  moisture,  but  it  is 
furnished  by  smaller  streams,  and  is  also  less  abundant  in*  some  tex- 
tures than  in  others ; for  example,  though  blood  vessels  susceptible 
of  conveying  red  blood  do  ramify  through  tendons  and  ligaments, 
yet  they  are  not  numerous,  apparently ; not  more  so,  indeed,  than 
what  is  sufficient  to  keep  up  by  a deposite  of  serum,  the  flexibility 
of  those  parts.  The  vascularity  of  a part  during  life  may  be  ascer- 
tained by  a simple  process  after  death,  the  most  vascular  always  lose 
proportionately  of  their  bulk  by  drying ; for  example,  a muscle  shrinks 
more  than  a tendon,  a gland  more  than  a muscle, 

Besides  the  operation  of  the  lymphatics,  much  of  the  super-abum 
dant  moisture  is  carried  oft  by  insensible  perspiration  and  evapora- 
tion from  the  surface  of  the  body : the  latter  process,  however,  is 
much  restrained  by  the  peculiar  character  of  the  cuticle,  without 
which  it  would  become  excessive,  probably  so  much  so  as  to  exceed 
any  supply  of  fluid  through  the  stomach. 

The  red  globules  of  the  blood,  besides  their  less  obvious  uses, 
unquestionably  serve  to  inspissate  the  serous  or  watery  part,  by  an 
intimate  mixture  with  it,  and  thereby  put  a certain  restraint  upon  its 
extravasation.  They  also,  from  their  size,  serve  to  keep  open  the 
channels  through  which  the  blood  circulates.  So  much  associated 
is  the  existence  of  red  globules  with  regular  blood  vessels , that  there 
are  but  few  examples  of  animals  having  the  former,  without  also 
having  the  latter ; whereas,  in  animals  whose  circulating  fluid  has 
not  red  globules,  but  is  a mere  serum,  the  entire  destitution  of  regular 
blood  vessels  is  very  common,  and  their  circulation,  if  the  name  be 
deserved,  consists  simply  in  the  transmission  of  moisture  from  one 
pore  to  another,  as  occurs  in  a rag  or  in  a sponge,  by  mere  capillary 
attraction.  Such  animals  form  a numerous  class  in  the  chain  of  or- 
ganized beings,  and  have  a gelatinous  consistence. 

A remarkable  feature  in  the  vascular  system,  both  arteries  and 
veins,  is  the  disposition  of  trunks  to  run  into  one  another ; or  to  form 
an  anastomosis,  whereby,  if  the  blood  should  be  cut  off  by  one  route, 
it  may  still  be  supplied  through  another.  These  communications 
are  frequent  in  the  head,  in  the  neck,  in  the  thorax,  in  the  abdomen, 


188 


CIRCULATORY  SYSTEM. 


and  in  the  extremities;  they  exist,  indeed,  wherever  the  blood  ves- 
sels do,  and  become  more  numerous  as  the  blood  vessels  are  smaller, 
or  more  removed  from  the  centre  of  the  circulation.  It  is  unneces- 
sary here  to  specify  instances,  as  the  more  remarkable  ones  will  be 
mentioned  at  a proper  time.  But  some  estimate  may  be  made  of 
their  importance,  and  of  the  facility  of  communication  established 
by  them,  when  it  is  remembered  that  cases  have  occurred  of  ob- 
structed aorta,  without  the  circulation  ceasing  in  the  parts  of  the 
body  beyond  it : the  same  has  occurred  to  the  venae  cavae,  and  to 
the  thoracic  duct  also.* 

The  extreme  vascular  ramifications  are  called  Capillaries,  ( Vasa\ 
Capillaria,)  and  they  form  the  connexion  between  the  arteries  and 
veins;  or,  by  being  intermediate  to  the  two,  they  are  the  ultimate 
terminations  of  the  arteries,  and  the  commencing  roots  of  the  veins. 
From  the  extreme  tenuity  of  these  vessels,  it  is  impossible  to  indi- 
cate where  the  arteries  terminate  and  the  veins  begin  ; yet  their  con- 
tinuity with  the  capillary  system  has  been  repeatedly  demonstrated, 
by  throwing  injections  from  the  one  into  the  other  system  ; and  by 
microscopical  observations  made  on  the  transparent  parts  of  living  ani- 
mals, as  the  mesentery  and  the  web  foot  of  frogs,  and  the  tail  of  fishes. 
These  facts  are  sufficiently  substantiated  by  the  observations  of  Mal- 
pighi, Leeuwenhoeck,  Prochaska,  and  a crowd  of  others;  yet  there 
are  anatomists  who  hold  a contrary  doctrine,  and  admit  the  paren- 
chyma of  the  ancients  (an  indefinable  something,  conceived,  how- 
ever, to  be  spongy)  as  a point  of  termination  for  the  arteries,  and  of 
commencement  for  the  veins. 

Though  the  capillaries  are  all  too  fine  to  be  seen  distinctly  without 
the  microscope,  yet  they  are  found  to  have  several  gradations  of  size. 
The  largest  of  them  are  those  which  only  escape  the  naked  eye,  ex- 
periencing successive  divisions,  whereby  their  diameters  are  reduced 
from  admitting  a file  of  several  globules  of  blood  to  the  caliber  of  one 
globule  only 4 The  capillaries  have  also  frequent  anastomoses  with 
one  another.  Sometimes  the  artery  is  simply  doubled  on  itself,  and 
immediately  becomes  a vein : on  other  occasions,  several  capillary 
arteries  run  into  the  same  vein. 

The  anastomoses  finally  end  in  a continuous  intertexture  of  ves- 

* Bedard,  Apat.  Gen  . 
f Anat.  Atlas,  Figs.  431,  432,  433. 
j;  Bedard,  loc.  eit. 


CAPILLARIES. 


189 


sels,  which  is  common  to  the  arteries  and  veins  both.  Although  the 
limits  of  the  two  sets  of  vessels,  can  not  be  precisely  defined,  so  as 
to  learn  where  one  set  ends,  and  the  other  set  begins,  yet  the  capil- 
lary  system  may  be  known  by  the  greater  uniformity  of  size  in  its 
vessels. 

Their  diameter  varies  from  the  to  the  of  an  inch,  but 
the  medium  measurement  is  from  the  tsVo  to  jtW  of  an  inch.  The 
following  table  will  show  the  result  of  measurements  upon  injected 
preparations : 


Brain  . 

- -I-* 

fT  (TO 

according  to  Weber. 

Kidney 

a tO  j--35o' 

cc  Muller. 

Ciliary  processes 

T‘T5t 

cc  cc 

Mucous  Membrane  7 

of  Large  intestine  $ 

1 1 

* TsTl  LU  17^4: 

u Weber. 

Lymphatic  Gland 

T8 IT  1 to  Zt'oS 

cc  cc 

Skin  . 

T l'iS 

cc  cc 

Inflamed  Membrane 

1SZ8  to  5 8 IB- 

cc  cc 

As  a general  rule  their  diameter  maybe  stated  at  from  one  to  five 
globules  of  red  blood.* 

By  the  above,  it  will  be  seen  that  their  diameter  is  sufficiently 
large  for  transmitting  the  blood  discs.  But  the  capillaries  are  de- 
cidedly smaller  than  any  of  the  tubular  structures  of  the  body. 

The  capillaries  pass  between  the  primitive  fibrils  of  muscles  and 
nerves,  and  form  an  intertexture  around  them,  but  as  in  other  tissues 
of  a very  fine  kind,  they  do  not  penetrate  them,  because  those  tis- 
sues have  in  their  elementary  filaments  a finer  diameter,  than  either 
the  capillaries,  or  even  the  red  globules  of  the  blood. 

When  the  capillary  communications  are  unduly  enlarged,  they 
constitute  what  has  been  called  by  Mr.  John  Bell  the  aneurism  from 
anastomosis,  a frequent  mark  in  young  children,  and  which,  when 
it  has  developed  itself  fully,  has  a spongy  structure  resembling  the 
erectile  tissues,  as  the  corpus  cavernosum  penis,  &c.  As  there  is 
a double  circulation,  so  there  is  a double  capillary  system,  one  for 
the  lungs  and  the  other  for  the  body  generally : to  these  may  be 
added  a third,  which  exists  in  the  liver  between  the  hepatic  extremi- 
ties of  the  venaportarum  and  the  hepatic  veins. 

The  texture  of  the  capillary  vessels  is  too  fine  to  admit  of  much( 


* Beclard,  loe.  cit. 

17  * 


190 


CIRCULATORY  SYSTEM. 


scrutiny,  but  they  appear  as  simple  cylindrical  excavations  in  the 
substance  of  the  part  to  which  they  belong.  This  appearance  has 
led  many  respectable  anatomists  to  the  conclusion,  that  they  were 
absolutely  destitute  of  walls.  Gruithuisen  saw  the  blood  flowing  in 
free  spaces  between  the  acini  of  the  liver  in  the  frog.  Muller  saw 
the  same,  in  the  liver  of  the  larva  of  the  triton.  Wedmeyer  came  to 
the  same  conclusion,  in  witnessing  the  broad  currents  of  blood  with 
the  small  islets,  between  them  in  the  lungs  of  the  salamander.  There 
are  many  other  authorities  on  the  same  side.  On  the  contrary,  Leeu- 
wenhoeck,  Haller,  Spallanzani,  Proc.haska,  Bichat,  Berres  and  Ru- 
dolphi,  admit  the  existence  of  such  membranous  walls.  Without 
the  latter,  we  can  scarcely  account  for  the  anatomical  injection  of 
fluids,  passing  from  the  arteries  into  the  veins,  without  extravasation; 
and  for  currents  of  blood,  crossing  above  and  below  each  other, 
without  mixing.  Windischman  has  injected  in  the  cochlea  of  birds, 
the  blood  vessels  of  a very  soft  plicated  membrane,  which,  upon  being 
dissolved  in  water,  left  a beautiful  vascular  net  work  with  the  meshes 
empty.  Schwann  has  observed  in  the  capillaries  of  the  mesentery  of 
the  frog,  an  arrangement  of  circular  fibres,  and  Muller  after  injecting 
the  vessels  of  the  kidney  of  a squirrel  and  macerating  the  glandular 
structure  off,  found  the  capillaries  on  the  tubuli  uriniferi,  apparently 
independent  vessels.* 

It  is  not  improbable,  that  they  may  be  uninterrupted  continuations 
of  the  internal  coat  of  the  arteries  into  that  of  the  veins.  They  have 
striking  powers  of  extension  and  of  contraction,  and  are  easily  irri- 
tated. An  emotion  of  the  mind,  as  a sentiment  of  shame  or  a feel- 
ing of  resentment,  quickly  causes  those  of  the  face  to  become  turgid 
with  blood.  Local  stimuli  cause  congestions  in  them.  Cold,  the 
application  of  a weak  acid,  or  fear,  causes  them  to  contract ; though, 
under  the  influence  of  the  heart,  they  are  less  so  than  larger  vessels. 
Their  innumerable  channels  cause  a comparatively  languid  circula- 
tion of  the  blood  in  them,  for  reasons  rnentioned  ; and'  by  furnishing 
it  with  more  places  of  contact  with  their  parietes,  put  it  more  under 
nervous  influence  than  it  is  elsewhere. 

These  vessels  are  not  equally  abundant  in  all  the  textures  of  the 
body.  Their  quantity  may  be  ascertained  by  the  redness  which  a 
part  acquires  by  inflammation,  as  well  as  by  fine  injections:  the 
latter  proof  is  preferable,  as,  in  the  former,  it  is  difficult  to  distin- 


* Mu-ller,  Phys.  p.  230. 


CAPILLARIES. 


191 


guish  them  from  the  extravasations  which  also  occur  at  the  same 
time.  The  celebrated  injections  of  Ruysch,  from  their  unusual 
minuteness,  induced  him  to  think  that  every  solid  portion  of  the 
body  was  vascular,  yet  he  admitted  that  some  portions  were  more 
vascular  than  others,  thereby  conceding  to  his  antagonists,  that  some 
points  at  least  were  not  formed  by  bloodvessels.  In  the  microsco- 
pical examinations  of  living  animals,  for  example  the  frog,  it  is  seen 
that  in  their  feet  the  smallest  capillaries  are  separated  by  distinct 
intervals,  while  in  the  mucous  membrane  of  the  lungs  the  finest 
needle  cannot  have  its  point  inserted  without  opening  several  of 
them.*  The  younger  an  animal  is,  the  more  vascular  are  its  parts: 
but,  on  the  contrary,  as  it  advances  in  age,  the  proportion  of  parts 
not  susceptible  of  injection  increases,  while  the  capillaries  diminish 
in  number.  In  cold-blooded  animals,  it  is  very  evident  that  some 
of  these  capillaries,  or  arterio-venous  communications,  are  large 
enough  to  admit  a file  of  several  red  globules  abreast,  while  others 
allow  a single  file  only. 

The  arrangement  of  the  capillary  net-work  is  for  the  most  part 
uniform,  the  principal  variation  being  in  the  size  of  the  meshes,  and 
in  their  being  elongated  or  not.  In  muscles  and  nerves,  the  elon- 
gation is  in  the  direction  of  the  primitive  fibrils,  and  the  same  may- 
be said  of  every  tissue  consisting  of  parallel  filaments.  In  the  in- 
testines, the  capillary  vessels  being  first  arborescent,  they  anastomose 
very  freely;  in  the  placenta  they  resemble  a tuft,  in  the  spleen  a 
sprinkling  brush,  in  the  tongue  a hair  pencil,  in  the  liver  a star,  in 
the  testicle  and  choroid  plexus  of  the  brain  a lock  of  hair,  in  the 
Schneiderian  membrane  a fine  trellis  work.  In  the  cortical  portion 
of  the  kidney,  there  are  glomeruli  or  small  bulbs  of  vessels  in  the 
midst  of  the  common  anastomosis  and  fine  vascular  net-work; 
having  wound  itself  up  in  that  way,  the  artery  then  emerges  on  the 
other  side,  and  is  lost  in  the  adjacent  capillary  tissue.  This  is 
said  according  to  Teidemann  to  be  particularly  distinct  in  the  triton 
and  salamander.  At  the  extremity  of  the  villus  of  the  human  pla- 
centa a minute  artery  is  directly  continuous,  with  a minute  returning 
vein. 

In  the  medullary  portion  of  the  kidneys,  in  company  with  the 
ducts  of  Bellini,  the  arteries  and  veins  run  parallel  with  these  ducts 


* Beclard,  Anat.  Gen. 


192 


CIRCULATORY  SYSTEM. 


anastomose  across  them  forming  elongated  meshes,  and  finally  ap- 
pearing on  the  papillm  renculi,  terminate  in  a fine  net-work,  sur- 
rounding the  orifices  of  the  uriniferous  ducts.  This  vascular  ar- 
rangement is  frequently  mistaken  for  the  tubuli  uriniferi  themselves. 


Fig.  32. 


Distribution  of  Capillaries 
in  the  Villi  of  an  Intestine. 


Fig.  33. 


Distribution  of  Capillaries 
around  the  follicles  of  a Mucous 
Membrane. 


The  most  attenuated  capillary  net-work  exists  in  the  lungs,  and 
in  the  choroid  membrane  of  the  eye.  The  interspaces  are  some-, 
what  larger  in  the  iris  and  ciliary  body.  The  mucous  membrane 
of  the  intestines,  especially  of  the  veins,  has  its  capillary  net-work 
so  fine  as  to  form  almost  the  entire  structure  apparently,  when  it 
is  successfully  injected.  Bones,  ossific  cartilages,  tendons,  liga- 
ments, and  the  fibrous  structures,  generally  are  furnished  with  the 
fewest  of  them,  and  have  the  largest  meshes. 


Fig  34. 


Distribution  of  Capillaries 
around  the  follicles  of  the  Parotid 
Cland. 


Fig.  35. 


Capillary  Network  of  the 
Nervous  Centres. 


The  nutrition  of  the  body  depends  upon  an  alteration  of  exhala- 
tion and  of  absorption  ; but  it  is  still  undetermined,  whether  there 
be  any  vessels  whatever  whose  especial  office  is  that  of  exhalation, 
and  which  produce  the  several  secretions  and  exhalations.  If  there 
be  such,  they  are  generally  designated  by  (he  term  exhalants,  and 
their  diameters  are  loo  small  to  transmit  the  red  globules  of  blood ; 


EXHALANTS. 


193 


their  function  is,  consequently,  to  give  passage  to  the  serous  particles 
only. 


palpebral  conjunctiva. 

This  subject  has  been  much  agitated  by  anatomists,  and  marshals 
the  best  authorities  on  both  sides.  Among  the  distinguished  advo- 
cates in  the  affirmative,  are  Boerhaave,  Haller  and  Bichat  ; and  op- 
posed to  them,  are  Prochaska,  Mascagni,  and  Richerand.  The 
leading  facts  of  the  former  are  ; The  microscopical  observations  of 
Leeuwenhoeck,  who  speaks  of  vessels  admitting  only  serous  globules  ; 
the  phenomena  of  inflammation,  which  render  red,  parts  naturally 
white  and  transparent : the  difficulty  of  conceiving  how  the  nourish- 
ment of  certain  parts  can  be  maintained,  whose  capillary  system  of 
red  blood  is  so  limited,  in  proportion  to  points  not  susceptible  of  it. 
The  opinion  of  Mascagni  and  others  to  the  contrary,  is  : That  those 
exhalants,  if  they  existed,  should  be  seen  readily,  inasmuch  as  they 
are  within  the  range  of  a microscope,  whose  powers  enable  one  to 
examine  a body  much  smaller  than  a red  globule  of  blood;  that  in- 
jections should  penetrate  them,  instead  of  being  limited  to  vessels 
whose  existence  is  sufficiently  confirmed  by  examination  in  the 
living  state  ; that  if  during  inflammation  they  do  seem  to  be  injected 
with  red  blood,  the  appearance  is  delusive,  and  depends  upon  the 
existing  capillaries  being  dilated  so  as  to  receive  more  red  blood 
than  usual,  upon  the  formation  of  new  vessels,  and  upon  sangui- 
neous infiltration;  and  as  to  membranes  naturally  white,  as  the  con- 
junctiva, the  colour  depends  upon  the  capillaries,  while  in  a healthy 
state,  being  so  small  that  they  do  not  admit  the  red  globules  in  a 
file  sufficiently  numerous  to  be  perceived  by  the  eye  ; the  globules 


Fig.  36. 


Fig.  37. 


Capillary  Network  in 
the  mucous  membrane  of  the 


Capillary  Network  in  the 
choroid  coat  of  the  eye. 


194 


CIRCULATORY  SYSTEM. 


being,  probably,  then  conducted  in  a series  of  one  only,  or  in  a 
single  fde,  like  a string  of  beads.  It  is,  therefore,  much  more  rea- 
sonable not  to  admit  the  existence  of  vessels  which  it  is  very  doubt- 
iul  whether  any  one  has  seen,  unless  we  claim  as  such  the  vessels 
which,  under  ordinary  circumstances,  do  not  convey  red  blood, 
at  least  in  a visible  manner ; but  are  limited  to  the  carrying  of  the 
liquor  sanguinis,  or,  in  other  words,  pure  serous  vessels,  the  exist- 
ence of  which  is  affirmed  by  Muller. 

When  a watery  injection  is  pushed  into  a blood  vessel,  it  in  a 
little  time  shows  itself  as  a fine  dew  upon  the  surface  of  the  serous 
and  mucous  membranes ; in  the  cellular  membrane,  and  elsewhere. 
According  to  many  anatomists,  it  has  gone  through  the  system  of 
exhalants,  and,  indeed,  presents  itself  to  sight  in  very  much  the  same 
way  that  exhalation  occurs  in  the  living  state.  From  the  view  which 
has  just  been  taken,  it  becomes  more  probable,  that  this  perspira- 
tion is  execufed  through  the  interstices  or  pores  of  the  vessels.  In 
the  dead  state  it  is  merely  a mechanical  result,  a simple  straining  of 
the  fluid;  whereas,  in  the  living  body  it  is  a Antal  function,  continu- 
ally modified  by  the  peculiar  vital  powers  of  the  organ  or  membrane 
where  it  occurs  ; and,  therefore,  presents  itself  under  the  form  of  the 
different  secretions.  The  question  of  the  exhalants  being  a distinct 
set  of  vessels,  does  not,  however,  appear  to  be  one  of  much  conse- 
quence ; because,  if  they  do  exist,  they  must  be  very  short  and  very 
small : and  the  assumption  of  their  existence  does  not  throAV  an) 
light  upon  the  function  of  secretion.  For  the  latter  is  still  an  incom- 
prehensible vital  process,  and  as  far  as  Ave  have  any  idea  about  it, 
it  is  quite  as  easy  to  conceive  of  its  being  performed  in  the  parietes 
of  the  capillaries,  as  in  the  mouths  of  a distinct  set  of  vessels,  whose 
length  is  too  short  to  admit  of  an  estimate. 

Besides  the  supposed  existence  of  a general  system  of  exhalant 
vessels,  some  anatomists  have  thought  that  there  vvas  a species  of 
them  acting  particularly  as  nutritive  vessels.  According  to  Boer- 
haave,  every  part  must,  therefore,  be  vascular.  Mascagni  thought 
that  the  extreme  arterial  ramifications  are  not  only  furnished  Avith 
exhaling,  but  also  Avith  nutritive  porosities ; and  that  there  are  every 
where  orifices  of  absorbing  vessels,  to  contain  the  nutritive  mole- 
cules. The  theories  of  Bichat  and  of  Prochaska,  do  not  differ  ma- 
terially from  the  latter.  Whatever  may  be  the  mode  of  existence, 
and  the  route  of  nutriment  to  the  several  parts  of  the  body,  the  opera- 
tions involved  are  entirely  too  subtle  even  for  microscopic  observa- 


TEXTURE  OF  THE  ARTERIES. 


195 


tion.  We,  therefore,  can  only  understand,  in  a general  way,  that 
the  blood  vessels  deposite,  and  the  lymphatics  absorb,  by  invisible 
avenues  in  the  cellular  substance,  the  molecules  of  composition  and 
of  decomposition  in  our  organs.*  It  is  to  this  power  that  the  name 
of  vital  force  has  been  given,  and  especially  that  of  the  force  of  for- 
mation, ( nisus  formativus.) 

The  arteries,  though  commonly  said  to  be  cylindrical  canals,  are 
not  exactly  so,  but,  as  they  recede  from  the  heart,  increase  somewhat 
in  diameter,  even  where  they  do  not  send  off  any  branches.  In  this 
way  the  arteries  of  the  umbilical  chord  are  evidently  larger  as  they 
get  nearer  the  placenta ; and  the  spermatic  arteries  of  a bull  as  they 
get  nearer  to  the  testicle.  Observations  made  on  the  carotid  arteries 
of  the  camel,  and  of  the  swan,  by  Mr.  Hunter,!  tend  to  prove  the 
same  disposition  in  them.  The  vertebral  arteries  afford  a striking 
example  of  the  same.  It  is  probable  that  the  rule  extends  to  all 
arteries  throughout  the  system,  but  it  cannot  be  ascertained  with  so 
much  certainty,  because  of  the  close  succession  of  branches  which 
they  send  off. 

Arteries  have  within  themselves  a power  of  increase  connected 
with  the  exigencies  of  the  part  to  which  they  go ; thus,  the  uterine 
arteries  increase  much  in  their  capacity  during  pregnancy,  while  the 
hypogastric,  from  which  they  are  derived,  augment  inconsiderably, 
and  the  primitive  iliacs  notin  an  appreciable  manner.  In  animals 
of  the  deer  kind,  whose  horns  are  deciduous,  the  same  augmentation 
of  arterial  trunks  occurs  while  the  horn  is  growing.  Tumours  are 
supplied  in  the  same  way.  But  in  all  these  cases,  after  the  exigency 
is  passed,  the  vessels  diminish  to  their  primitive  size. 

With  the  exception  of  the  semi-lunar  valves  at  the  orifice  of  the 
pulmonary  artery  and  of  the  aorta,  there  are  no  others  in  the  whole 
arterial  system.  These  valves  permit  the  blood  to  pass  in  the  direc- 
tion of  the  circulation,  but  not  backwards,  as  they  are  closed  imme- 
diately upon  the  cessation  of  the  contraction  of  the  ventricles.  The 
tricuspid  valve  of  the  heart,  and  the  semi-lunars  of  the  pulmonary 
artery,  are  naturally  not  so  perfect  in  their  closure  as  those  on  the 
other  side  of  the  heart,  but  permit  a small  quantity  of  blood  to  retro- 
grade*! As  life  advances,  the  valves  of  the  aorta  are  much  disposed 
to  ossification  and  derangements  of  different  kinds,  which  render 
them  much  less  perfect  than  those  of  the  pulmonary  artery. 

* Bedard,  loc.  cit. 

f On  the  Blood  and  Inflammation.  f Hunter,  loe.  cit. 


196 


CIRCULATORY  SYSTEM. 


CHAPTER  II. 

Of  the  Tcxtnre  of  the  Arteries. 

The  arteries  are  composed  of  three  coats,  an  external,  a middle, 
and  an  internal. 

The  External  Coat,  also  called  Cellular,  is,  in  fact,  condensed 
cellular  substance  formed  into  a cylinder.  Its  fibres  run  in  every 
direction,  so  as  to  be  perfectly  interwoven  with  one  another.  The 
exterior  periphery  of  this  coat  is  continued  into  the  adjacent  cellular 
substance,  but  its  internal  face  is  united  more  closely  to  the  middle 
coat ; not,  however,  so  tightly  as  to  prevent  a slight  sliding  of  the 
one  upon  the  other,  and  to  forbid  their  easy  separation  by  a knife. 
Scarpa  is  not  disposed  to  admit  this  as  one  of  the  coats  of  arteries, 
and  says  that  it  only  serves  as  an  exterior  envelope,  and  retains  them 
in  their  places.  This  coat  manifests  its  fibrous  character  in  not  being 
disposed  to  secrete  fat,  and  is  more  distinct  in  the  large  arterial  trunks. 
It  has  considerable  strength  and  elasticity,  both  circularly  and  longi- 
tudinally, and  is  remarkable  for  its  whiteness.  If  an  artery  be  sur- 
rounded by  a tightly  drawn  ligature,  the  middle  and  the  internal 
coats  will  be  completely  cut  through  by  it,  while  the  external  coat 
remains  entire.  This  coat,  then,  answers  the  purpose  of  a strong 
investing  fascia,*  in  which  respect  it  may  be  considered  as  a sheath 
to  the  proper  arterial  structure,  though  the  term  sheath  is  commonly 
applied  to  the  cellular  membrane  on  its  outer  side. 

The  Middle  Coat  of  the  arteries  is  called  the  Muscular,  the  Proper, 
the  Tendinous,  and  so  on.  It  is  of  a light  yellowish  tinge,  and  de- 
creases continually  in  thickness,  with  but  few  exceptions,  from  the 
heart  to  the  ends  of  the  arteries;  it  is,  however,  proportionately 
thicker  in  the  small  arteries  than  in  the  large  ones.  Its  fibres  are 
circular,  but  do  not  individually  perform  the  circuit  of  the  vessel. 
They  are  parallel  to  each  other,  and  adhere  laterally  by  very  slender 
ties.  In  the  larger  arteries,  this  coat  may  be  divided  into  several 
laminae,  though  the  division  is  entirely  artificial.  There  are  no  lon- 


* Jones  on  Hemorrhage. 


TEXTURE  OF  ARTERIES. 


197 


gitudinal  fibres  whatever  in  it ; the  consequence  of  which  is,  that  an 
artery  divested  of  its  external  coat,  yields  more  readily  in  the  direc- 
tion of  its  length  than  of  its  circumference. 

The  middle  coat  has  a firmness,  whereby,  even  when  an  artery  is 
emptied,  the  cylindrical  shape  is  still  retained.  Its  character  seems 
to  be  the  result  of  a mixture  of  elastic  and  of  muscular  properties 
derived  from  a state  of  tissue  entirely  peculiar;  but  which  some  ana- 
tomists have  been  very  desirous  of  ranging  under  the  head  of  mus- 
cles, others  under  that  of  ligaments,  and  a third,  under  both  united. 
The  celebrated  John  Hunter,  whose  observations  were  generally 
made  with  the  most  scrupulous  attention  to  perfect  exactitude ; were 
often  repeated,  so  as  to  make  one  confirm  another;  and  who  has 
received  that  sanction  of  greatness  in  which  one’s  posthumous  repu- 
tation becomes  more  exalted  than  the  living ; bestowed  much  atten- 
tion on  this  subject.  He  was  induced  to  believe  that  this  middle 
coat  was  formed  by  a muscular  lamina  internally,  and  an  elastic  one 
externally;  which  distinction  might  be  rendered  evident  by  cutting 
a contracted  artery  through  transversely , when  the  muscular  coat 
would  be  found  projecting  beyond  the  other.  He  acknowledges, 
however,  that  he  never  could  discover  the  direction  of  the  muscular 
fibres  ; though  he  supposed  them  to  be  oblique,  because  their  degree 
of  contraction  was  greater  than  a straight  muscle  could  produce. 

The  elastic  contraction  of  an  artery,  is  manifested  both  in  the  di- 
rection of  its  length  and  of  its  circumference  ; for,  when  put  upon  the 
stretch  in  either  way,  it  has  the  ability  of  returning  to  its  original  di- 
mensions after  the  distending  force  ceases.  The  muscular  contrac- 
tion, however,  only  occurs  in  the  circumference,  and  not  at  all  in 
the  length:  by  it  the  caliber  of  arteries  is  reduced  to  a very  small 
diameter,  if  an  animal  be  slowly  bled  to  death.  If,  in  this  con- 
tracted condition,  an  artery  be  slit  open  longitudinally , the  elastic 
coat  will,  at  the  cut  margin,  project  beyond  the  other,  which  Mr. 
Hunter  considers  as  another  way  of  ascertaining  the  existence  of  the 
two  tunics.  But  if  this  same  artery  be  then  stretched  transversely, 
the  muscular  coat  will  project  beyond  the  other ; for  the  reason,  that 
if  a muscle,  after  death,  be  elongated  by  force,  it  has  no  power  of 
returning  from  that  state,  but  will  remain  precisely  as  it  is:  whereas, 
elasticity  being  a property  of  matter  enjoyed  quite  as  fully  in  the 
dead  as  in  the  living  state,  the  elastic  coat  of  the  artery  returns  to 
the  medium  condition. 

Mr.  Hunter,  with  a view  of  satisfying  himself  on  these  several 

Vol.  II.— 18 


198 


CIRCULATORY  SYSTEM. 


points,  had  a horse  bled  to  death,  so  as  to  obtain  the  vessels,  at  their 
minimum  of  contraction.  A circular  section  of  the  aorta  measured, 
at  first,  five  inches  and  a half,  and,  on  being  stretched,  it  lengthened 
to  ten  inches  and  a half;  being  let  alone,  it  contracted  to  six  inches, 
at  which  it  remained  stationary  ; the  difference  between  six  inches 
and  ten  and  a half,  was  then  the  amount  of  its  elastic  power,  while 
only  half  an  inch  of  contraction  was  due  to  the  muscular  stratum,  or, 
in  other  words,  an  eleventh  of  the  whole. 

A section  of  the  iliac  artery,  measuring  two  inches  in  circumfe- 
rence, on  being  allowed  to  contract  after  stretching,  measured  two 
and  one-third  inches;  it,  therefore,  gained  one-sixth  the  amount  of 
its  muscular  contraction.  A section  of  the  axillary  artery  gained 
one-eighth — of  the  carotid,  two-thirds — of  the  radial  artery,  doubled 
its  primitive  extent.  From  all  which  the  inference  was  drawn,  that 
the  power  of  recovery  in  a vessel  is  greater,  in  proportion  as  it  is 
nearer  the  heart,  but  lessens  as  the  distance  increases,  which  shows 
the  decrease  of  elastic,  and  the  increase  of  muscular  power. 

The  elastic  coat  gives  a middle  state  to  an  artery,  or  has  a con- 
tinued tendency  to  it ; if,  therefore,  the  artery  be  too  much  dilated, 
it  contracts  it,  and  if  it  be  too  much  contracted  it  dilates  it,  all  of 
which  is  readily  exemplified  by  a cylinder  of  gum  elastic,  which, 
whether  compressed  or  dilated  has  only  one  state  of  repose,  to  which 
it  immediately  returns  on  being  left  to  itself.  Mr.  Hunter  supposed, 
that  a certain  degree  of  elasticity  is  continued  to  the  very  end  of 
every  artery,  from  this  quality  being  better  suited  to  sustain  a per- 
manent resistance  than  muscular  power  ; as  a pipe  of  lead,  from  its 
want  of  elasticity,  finally  becomes  stretched  and  useless  under  the 
pressure  of  a column  of  water,  whereas,  one  of  iron,  from  being 
elastic,  always  reacts  efficiently.  It  is  this  elasticity  in  the  arteries, 
which  causes  the  blood,  at  a little  distance  from  the  heart,  to  flow 
through  them  in  a continued  jetting  stream  when  they  are  opened, 
although  it  is  supplied  to  the  aorta  by  interrupted  strokes.  In  this 
way,  as  the  artery  is  more  distant  from  the  heart,  the  stream  becomes 
proportionately  regular. 

“ The  muscular  power  of  an  artery  renders  a smaller  force  of  the 
heart  sufficient  for  the  purposes  of  circulation;  for  the  heart  need 
only  act  with  such  force  as  to  carry  the  blood  through  the  larger 
arteries,  and  then  the  muscular  power  of  the  arteries  takes  it  up, 
and,  as  it  were,  removes  the  load  of  blood  while  the  heart  is  dilating. 
In  confirmation  of  this  remark,  it  is  observable  in  animals  whose 


TEXTURE  OF  THE  ARTERIES. 


199 


arteries  are  very  muscular,  that  the  heart  is  proportionably  weaker, 
so  that  the  muscular  power  of  the  vessels  becomes  a second  part  to 
the  heart,  acting  where  the  power  of  the  heart  begins  to  fail,  and 
increasing  in  strength  as  that  decreases  in  power.”* 

After  many  discussions  on  the  above,  the  present  state  of  micro- 
scopical anatomy  may  be  considered  as  leading  to  the  following  con- 
clusions. The  fibres  which  make  the  middle  coat  of  the  arteries  are 
identical  with  those  of  the  ligamenta  flava  of  the  vertebral  column 
and  the  analogous  tissue,  as  the  elastic  ligamentous  structure  of  the 
trachea,  and  the  vocal  or  crico-thyroid  ligaments  of  the  larynx.  This 
elastic  tissue  is  every  where  distinguished  by  the  great  inequality  in 
the  size  of  its  fibres,  and  by  their  anastomosing  with  each  other.  It 
is  of  a yellow  colour,  and  its  elasticity  is  well,  though  not  fully  pre- 
served in  alcohol  for  an  indefinite  duration.  This  elasticity  is  an 
almost  purely  physical  quality,  both  in  the  living  and  dead  state,  not 
absolutely  so,  but  a near  approach  to  it. 

Among  the  traits  which  distinguish  the  middle  coat  of  the  arteries 
from  muscular  tissue,  is,  its  not  contracting  under  the  strongest  elec- 
tric and  galvanic  stimuli,  like  muscles  commonly.  Nysten  repea- 
tedly experimented  with  galvanism  on  the  aorta  of  criminals  just 
beheaded,  but  did  not  perceive  the  slightest  contraction  of  its  fibres. 
Similar  experiments  with  the  same  results  have  been  instituted  by 
many  others,  and  amongst  them  Muller,  f 

The  fibres  of  the  elastic  tissue  are  prismatic,  or  four  sided,  and 
have  a diameter  from  ' . to  —7-  of  an  inch.  In  the  coat  of  the 
arteries  their  course  is  more  decidedly  circular  and  parallel  than  in 
the  ligaments.  In  both  cases  the  heat  of  boiling  water  draws  them 
up,  but  does  not  destroy  their  elasticity. 

The  Internal  Coat  of  the  arteries  is  designated  by  the  terms  Ner- 
vous and  Arachnoid.  It  is  continued  from  the  ventricles  of  the 
heart,  in  the  left  one  of  which  it  is  of  greater  thickness.  It  is  the 
duplication  of  this  membrane  with  some  fibres  interposed,  that  com- 
poses the  semi-lunar  valves  of  the  aorta  and  of  the  pulmonary  artery. 
Its  internal  face  is  smooth,  polished,  and  moistened  wfith  a kind  of 
humidity  which  permits  the  blood  to  flow  through  with  diminished 
friction.  In  the  larger  arterial  trunks,  some  small  longitudinal 
wrinkles  are  observable  in  it ; and  when  an  artery  has  been  cut 
through,  as  in  amputation,  it  is  disposed  to  retract  in  small  trans- 


* Hunter,  loc.  cit. 


f Loc.  cit.,  p.  217. 


200 


CIRCULATORY  SYSTEM. 


Yerse  wrinkles.  It  is,  therefore,  not  very  extensible,  but  has,  accord- 
ing to  the  experiments  of  Sir  Everard  Home,*  a considerable  degree 
of  solidity  and  strength. 

The  internal  coat  of  arteries  possesses,  to  a limited  extent,  the 
elastic  and  other  qualities  of  the  middle,  but  it  is  generally  considered 
as  belonging  to  the  class  of  serous  membranes.  A very  delicate 
layer  of  epithelial  scales  with  oval  nuclei,  according  to  Henle,  occu- 
pies its  internal  face.  This  coat  may  be  stripped  with  great  facility 
from  the  aorta  after  steeping  it  for  some  time  in  alcohol.  It  is  then 
found  to  be  very  thin  and  semitransparent. 

Ossifications  of  this  membrane  are  very  frequent  after  the  age  of 
sixty. 

In  addition  to  the  tunics  mentioned,  cellular  substance,  vessels, 
and  nerves  enter  into  the  structure  of  arteries. 

The  Cellular  Substance  is  not  abundant,  and  serves  principally  to 
unite  the  sides  of  the  circular  fibres  to  one  another,  and  to  join  the 
internal  to  the  middle  coat. 

The  Vessels  ( Vasa  Arteriarum ) consist  both  in  arteries  and  in 
veins,  and  come  from  the  adjacent  trunks,  instead  of  from  those  on 
which  they  ramify.  They  may  be  made  very  distinct  by  a fine  in- 
jection, or  by  laying  them  bare  in  the  living  body  ;■  when  in  a little 
time  after  exposure,  they  begin  evidently  to  carry  red  blood,  and  to 
grow  turgid  as  in  inflammation.  The  difference  in  the  colour  of  the 
blood  distinguishes  these  arteries  from  the  same  kind  of  veins.  Both 
arteries  and  veins  may  be  traced  very  well  into  the  middle  coat,  but 
not  upon  the  internal,  though  the  changes  which  occur  in  the  latter, 
from  disease  and  upon  the  application  of  ligatures,  prove  clearly 
that  exhalation  and  absorption  are  continually  going  on  there.  For 
in  inflamed  arteries,  an  exhalation  is  seen  upon  their  internal  surface, 
and  when  a coagulum  has  been  produced  by  ligature,  it  is  finally 
absorbed. 

The  Nerves  of  the  arteries,  according  to  Wrisberg  and  Beclard, 
are  numerous  and  considerable,  form  around  them  a plexus  resem- 
bling that  of  the  par  vagum  around  the  oesophagus,  and  follow  them 
into  the  interior  of  our  organs,  with  the  exception  of  the  brain  ; which 
has  them  only  to  its  surface.  They  are  proportionately  more  abun- 
dant in  the  aortic  than  in  the  pulmonary  system ; also  upon  the  smaller 

* Transactions  for  the  Improvement  of  Medical  and  Surgical  Knowledge, 
vol.  i. 


TEXTURE  OF  THE  ARTERIES. 


201' 


than  upon  the  larger  arteries.  The  arteries  of  the  head,  of  the  neck, 
of  the  thorax,  and  of  the  abdomen,  are  supplied  from  the  sympa- 
thetic nerve,  while  those  of  the  extremities  are  supplied  from  the 
nerves  of  the  spinal  marrow. 

The  passing  of  the  blood  through  the  arteries  is  accompanied 
with  a pulsating  motion,  which,  for  the  most  part,  is  exactly  syn- 
chronous with  the  contraction  of  the  left  ventricle,  and  depends 
upon  an  increased  quantity  of  blood  thrown  into  them  at  the  moment. 
The  dilatation  of  the  artery  may  be  both  seen  and  felt ; “but  were 
we  to  judge  of  the  real  increase  of  the  artery  by  this,  we  should 
deceive  ourselves;  for  when  covered  by  integuments,  the  apparent 
effect  is  much  greater  than  it  really  is  in  the  artery  itself ; for  in 
laying  such  an  artery  bare,  the  nearer  we  come  to  it,  the  less  visible 
is  its  pulsation ; and,  when  laid  entirely  bare,  its  motion  is  hardly 
either  to  be  seen  or  felt.  This  apparent  diastole  of  the  artery  is 
augmented  in  proportion  to  the  solid  matter  covering  it,  whence 
tumours  over  large  arteries  have  considerable  motion  given  to  them, 
and  have  often  been  supposed  to  be  aneurismal.  Arteries,  in  fact, 
during  their  diastole  or  dilatation,  increase  much  more  in  length 
than  in  width,  and  are  thrown  into  a serpentine  course:  instead, 
therefore,  of  the  term  diastole,  it  should  rather  be  called  the  elon- 
gated state.”*  Mr.  Parry,  of  Bath,f  has  denied  that  the  arteries 
dilate  at  all  during  their  diastole:  his  opinion  however,  is  peculiar, 
though,  in  an  experiment  performed  many  years  ago  upon  the  carotid 
artery  of  a calf,  its  correctness  appeared  to  me  then  to  be  fully 
proved. 

There  is  no  part  of  the  human  body  which  presents  more  fre- 
quent varieties,  in  different  individuals,  than  the  arteries.  These 
varieties  are  found,  in  their  place  and  manner  of  origin,  in  position, 
and  in  the  number  of  their  ramifications.  They  are  comparatively 
rare  in  the  trunks  of  the  first  order,  more  common  in  those  of  the 
second;  and  still  more  usual  in  those  of  the  third  and  fourth.  From 
these  causes,  discrepancies  are  continually  found  in  the  descriptions 
of  the  most  approved  authorities,  and  must  last  so  long  as  writers 
repose  upon  a partial  experience,  instead  of  referring  to  what  has 
been  most  generally  observed. 

* J.  Hunter,  loc.  cit.  f Experimental  Inquiry  on  the  Pulse,  1816-1819. 

18* 


202 


CIRCULATORY  SYSTEM. 


CHAPTER  III. 

Of  the  Texture  of  the  Veins. 

The  veins,  from  their  duty  of  receiving  the  blood  in  all  parts  of 
the  body  from  the  extreme  arteries,  and  returning  it  to  the  heart, 
by  successively  collecting  it  into  the  two  venae  cavse,  may  be  more 
appropriately  compared  to  the  roots  of  a tree,  than  to  its  branches. 
The  variations  in  them,  as  well  as  their  anastomoses,  are  more  fre- 
quent than  in  the  arteries. 

They  are  more  numerous  than  the  arteries;  for,  in  addition  to  two 
venous  trunks  attending  each  artery  wherever  the  structure  of  the 
part  is  intended  for  locomotion,  as  in  the  extremities,  and  in  some 
places  upon  the  trunk  of  the  body,  there  is  a very  abundant  class  of 
veins  which  are  superficial  or  subcutaneous,  and  which,  when  filled 
properly  with  injecting  matter,  form  a fine  vascular  net-work  over 
the  whole  surface  of  the  body.*  These  superficial  veins,  in  some 
places,  form  trunks  even  larger  than  such  as  attend  the  arteries,  and 
especially  in  the  extremities.  Besides  the  excess  in  number,  the 
veins  which  attend  the  arteries  (Fence  Comites)  have  a capacious- 
ness which,  in  many  cases,  is  double  that  of  the  latter.  From  these 
several  circumstances,  it  results  that  the  area  of  the  venous  system 
vastly  exceeds  that  of  the  arterial. 

In  some  cases  the  veins  follow  precisely  the  course  of  the  arteries, 
one  for  one,  as  in  the  greater  number  of  the  viscera  of  the  abdomen, 
where  they  have  common  points  of  entrance  and  departure.  Some- 
times two  arteries  discharge  into  one  vein,  as  in  the  penis,  the 
clitoris,  and  the  umbilical  chord  ; sometimes  they  pursue  a course 
entirely  different  from  the  arteries,  as  in  the  pia  mater.  For  the 
most  part  they  are  less  tortuous  than  the  arteries. 

The  veins,  when  injected,  assume  a cylindrical  shape,  yet  they 
differ  materially  from  the  arteries,  in  having  much  thinner  coats, 
and  in  being  so  pliable  that  they  collapse  by  their  own  weight.  In 
the  lower  extremities,  however,  near  the  feet,  and  upon  them  ; as 
the  veins  sustain  the  pressure  of  a long  column  of  blood,  they  have 

* Pauli  Mascagni  Anatom.  Magna.  Pisis,  1823, 


TEXTURE  OF  THE  VEINS. 


203 


additional  thickness  and  strength,  so  as  to  approximate  them  more 
to  the  arterial  structure.  This  provision  will  be  found  occurring  in 
most  places  where  they  have  much  duty  to  perform. 

“ They  are  similar  to  the  arteries  in  their  structure,  being  com- 
posed of  an  elastic  and  muscular  substance ; the  elasticity  preserves 
them  in  some  degree  in  a middle  state,  although  not  so  perfectly  as 
it  does  in  the  arteries.  The  muscular  power  adapts  the  veins  to  the 
various  circumstances,  which  require  the  area  to  be  within  the  middle 
state,  and  assists  the  blood  in  its  motion  towards  the  heart.”* 

The  External  Coat  is  thinner  and  not  so  strong  as  that  of  the 
arteries ; in  other  respects,  the  resemblance  is  sufficiently  close  not 
to  require  any  particular  comment. 

The  Middle  Coat,  near  the  entrance  of  the  larger  veins  into  the 
heart,  is  distinctly  muscular. f It  is  formed  of  soft  extensible  fibres, 
many  of  which,  when  the  vein  is  held  up  to  the  light,  appear  longi- 
tudinal, while  the  most  internal  are  circular;  there  are  difficulties, 
however,  in  the  separation  of  these  fibres,  which  prevent  their  course 
from  being  accurately  ascertained.  Admitting  this  coat  with  the 
exception  of  its  muscular  ingredient  near  the  heart,  to  be  of  the 
same  tissue,  that  is  the  elastic  ligamentous  which  prevails  in  the  ar- 
teries, yet  the  filaments  composing  it  are  much  more  decidedly  in- 
termixed, according  to  my  personal  observations.  Bichat  and 
Meckel  assert,  that  the  whole  of  them  are  longitudinal,  and  that 
there  are  none  circular. 

This  coat  in  the  human  subject,  is  much  thicker  in  the  system  of 
the  ascending  than  of  the  descending  cava  ; it  is  also  thicker  in  the 
superficial  than  in  the  deep-seated  veins.  In  some  subjects  it  is 
much  better  developed  than  in  others.  In  certain  parts  of  the  body 
it  is  entirely  deficient,  as  in  the  sinuses  of  the  dura  mater,  and  has 
its  place  supplied  by  this  membrane  ; the  same  deficiency  exists  in 
the  sinuses  of  the  bones. 

The  Internal  coat  is  more  delicate  and  extensible  than  the  corres- 
ponding one  of  the  arteries,  is  less  liable  to  rupture,  and  less  disposed 
to  ossification.  It  is  thrown  into  a considerable  number  of  duplica- 
tions, forming  valves.  Each  valve  is  of  a semicircular  shape ; is  con- 


* Hunter,  loc.  cit. 


f Beclard,  loc.  cit. 


204 


CIRCULATORY  SYSTEM. 


nected  by  its  curved  edge  to  the  Arein,  while  the  straight  edge  is  loose, 
and  turned  towards  the  heart.  When  the  veins  are  injected  back- 
wards, these  valves  may  be  forced  in  the  larger  trunks,  and  give 
them  a knotted  appearance.  The  valves  are  commonly  in  pairs, 
but  in  certain  veins,  as  the  crural  and  the  iliac,  there  are  three  of 
them  together ; very  rarely  do  they  amount  to  four.  In  some  in- 
stances there  is  but  a single  one  ; this  arrangement  is  more  frequent 
at  venous  orifices,  as  the  great  coronary  vein  of  the  heart,  the  vena 
cava  ascendens,  the  vena  azygos.  They  are  frequently  found  reticu- 
lated as  if  they  had  been  lacerated,  whence  it  has  been  supposed 
that  the  fibres  which  cross  the  sinuses  of  the  dura  mater  are  an 
elementary  approach  to  them. 

The  valves  are  more  abundant  in  the  superficial  than  in  the  deep- 
seated  veins,  but  they  do  not  exist  every  where.  There  are  none 
in  the  branches  of  the  vena  portarum,  excepting  the  vasa  brevia: 
none  in  the  spine,  in  the  umbilical  vein,  the  cervical  veins,  the  kid- 
neys, womb,  ascending  and  descending  cava,  or  in  the  median  vein. 
The  valves  are  proportionately  more  abundant  in  the  lower  extre- 
mities. 

From  the  tenuity  of  the  parietes  of  the  veins,  the  blood  may  be 
readily  distinguished  circulating  through  them.  Their  coats,  like 
those  of  the  arteries,  are  vascular,  or  have  the  vasa  vasorum.  The 
arteries  come  from  the  nearest  small  trunks,  while  the  corresponding 
veins  do  not  empty  immediately,  but  secondarily,  into  the  trunk, 
whose  parietes  they  supply.  They  are  well  furnished  with  veins. 

Their  elasticity,  both  transversely  and  longitudinally,  is  well 
marked ; but  they  are  not  so  extensible  in  the  latter  direction  as  the 
arteries,  while  they  are  more  so  transversely.  There  can  be  no  doubt 
of  their  spontaneous  powers  of  contraction,  for  it  is  abundantly  proved 
by  their  diminishing  much  in  volume  upon  the  application  of  cold ; 
moreover,  when  a venous  trunk,  distended  with  blood,  is  intercep- 
ted by  two  ligatures,  and  then  punctured,  it  empties  itself  entirely 
and  rapidly. 

The  circulation  in  the  veins  is  produced,  in  a principal  degree,  by 
the  contraction  of  the  heart;  their  own  contraction  may  also  favour 
this  motion,  as  wrell  as  lateral  pressure  from  contiguous. parts.  As 
the  movement  of  the  blood  in  the  smaller  arteries  is  so  uniform  as  to 
be  almost  without  pulsation,  so  the  latter  disappears  entirely  in  the 
veins.  It  is  not  clear  that  this  circumstance  depends  exclusively  on 


THE  BLOOD. 


205 


the  friction  experienced  by  the  blood  in  passing  through  the  capil- 
laries, but  is  probably  rather  owing,  as  Mr.  Hunter  has  suggested, 
to  the  veins  receiving  their  blood  from  different  arteries,  some  of 
whose  channels  are  more  circuitous  than  others,  and,  consequently, 
their  blood  arrives  at  different  times.  The  momentum  of  the  heart, 
then,  even  if  it  did  impinge  upon  those  channels,  would  not  be  syn- 
chronous upon  the  venous  trunk,  but  would  be  divided  in  such  a 
way  as  to  produce  a tremour  or  confused  motion.  The  larger  veins, 
however,  have  near  the  heart  a pulsation  during  the  contraction  of 
the  auricles,  arising  from  the  arrest  of  their  circulation  at  the  moment. 
During  inspiration,  the  vacuum  created  in  the  thorax  hurries  on  the 
blood  to  the  heart,  but  in  expiration  it  is  somewhat  impeded.* 

It  has  sometimes  happened,  that  a large  vein  near  the  heart  being 
opened  by  accident  or  an  operation,  a strong  inspiration  has  caused 
the  introduction  of  air,  which,  being  carried  to  the  heart,  has  pro- 
duced instant  death.  It  occurred  in  Paris  to  the  celebrated  surgeon 
Dupuytren,  and  has  occurred  to  others. 


CHAPTER  IV. 

Of  the  Blood. 

The  Blood  is  the  fluid  from  which  is  derived  the  aliment  for  the 
growth  and  repair  of  all  other  parts  of  tire  body.  It  is  renovated 
by  the  accession  of  new  nutriment  introduced  into  the  system 
through  the  process  of  assimilation,  and  it  has  also  a large  increase 
from  the  decomposed  materials  of  the  several  textures  of  the  body. 

* This  ancient  observation  has  lately  been  renewed,  with  additional  interest 
and  details  by  M.  Barry  of  Paris.  See  a Report  of  MM.  Cuvier  and  Dumeril, 
concerning  the  Influence  of  the  Atmosphere  on  the  Circulation  of  the  Blood,  in 
the  Philadelphia  Journal  of  the  Medical  and  Physical  Sciences,  for  July,  1826. 
M.  Barry  has  probably  assigned  too  much  importance  to  this  influence,  as  it 
is  certain  that  the  circulation  may  go  on  very  well  where  no  vacuum  is  pro- 
duced at  intervals  in  the  thorax;  for  example,  in  the  foetus,  in  incubation,  and 
in  fish. 


206 


CIRCULATORY  SYSTEM. 


A copious  excretion  takes  place  from  it  through  the  different  glands 
and  emunctories.  The  precise  manner  of  its  formation  is  im- 
perfectly understood ; it  would  at  least  seem  to  require  no  very 
complex  apparatus  for  its  formation,  as  it  is  generated  in  the  area 
vasculosa  of  the  germinal  membrane  of  an  egg,  before  the  organs 
exist  in  a distinct  state. 

The  Blood,  in  the  human  subject,  and  in  many  animals,  is  of  a 
red  colour.  It  is  about  the  consistence  of  thin  size,  has  a peculiar 
smell,  a nauseous  and  slightly  saline  taste,  and  is  somewhat  heavier 
than  water ; its  specific  gravity  being  about  105,  and  its  temperature 
in  the  living  body  is  from  96  to  98°  of  Fahrenheit. 

The  method  devised  by  Mr.  Valentin  to  determine  the  exact 
proportion  and  quantity  of  blood  in  an  animal  has  the  merit  of 
greater  exactitude  than  any  other,  and  seems  to  have  solved  this 
question  with  an  accuracy  almost  unexceptionable.  The  weight  of 
the  animal  is  first  ascertained  ; a certain  quantity  of  blood  is  then  re- 
moved, and  evaporated  to  dryness ; the  weight  of  the  residuum  is 
then  ascertained.  A known  quantity  of  water  distilled  is  upon 
drawing  the  first  blood,  thrown  in  by  the  same  orifice  and  allowed  to 
mix  with  the  general  mass  of  blood.  This  done,  a second  quantity 
of  blood  equal  to  the  first  is  withdrawn,  evaporated  to  dryness  also, 
and  the  wreight  of  its  solid  residuum  ascertained.  The  quantity  of  the 
residuum  in  the  two  parcels,  determines  the  entire  amount  of  blood 
in  the  animal  by  the  following  method : 

Thus,  let  two  ounces  of  blood  first  drawn  yield  twenty-four  grains 
of  solid  matter ; and  upon  the  injection  of  one  pint  and  a half  of 
water  let  two  other  ounces  of  blood  yield  only  twenty-one  grains  of 
solid  matter.  Then  multiply  the  quantity  of  wmter  injected  by 
twrenty-one  and  divide  by  three,  (the  difference  in  the  tv'o  parcels 
of  solid  residuum  :)  the  result  will  determine  the  whole  quantity  of 
blood  in  the  animal  after  the  extraction  of  the  first  two  ounces. 
Thus  24  ounces  multiplied  by  twenty-one  and  divided  by  3,  gives 
168  ounces.  Tried  by  this  method,  a dog  of  531bs.  weight  is  ascer- 
tained to  have  ten  and  a half  pounds  of  blood,  and  forty-two  and 
a half  pounds  of  other  materials  in  his  composition,  or  one  part  of 
blood,  and  four  parts  nearly  of  other  constituents. 

There  are  some  circumstances  which  may  affect  the  absolute  ac- 
curacy of  the  experiment,  but  the  conclusion  is  so  nearly  satisfactory 
that  Mr.  Valentin  in  taking  the  dog  as  the  standard  for  the  human 
body  fixes  the  quantity  of  blood  in  a man  at  thirty-four  and  a half, 


THE  BLOOD. 


207 


and  in  a woman  at  twenty-six  pounds : the  proportion  in  the  first 
being,  blood,  1 ; other  parts,  4-30 : and  for  the  female,  blood,  1 ; 
and  other  parts,  4-93. 

A remarkable  fact  was  observed  in  an  emaciated  and  diseased 
dog,  that  the  relative  quantity  of  blood  to  other  parts  was  the  same 
as  in  health. 

If  the  blood  be  examined  microscopically  while  circulating  in  an 
animal,  or  immediately  upon  being  drawn,  it  is  seen  to  consist  of 
red  particles  or  globules  swimming  in  a transparent  fluid.  This 
transparent  fluid  is  the  Liquor  Sanguinis  or  Plasma,  which  is  formed 
of  serum  and  fibrin,  the  latter  being  in  a state  of  solution  in  the 
serum.  This  state  of  solution  has  been  proved  by  Muller  in  filter- 
ing through  a porous  paper  the  blood  of  a frog  recently  drawn  : from 
the  size  of  the  red  particles  they  are  in  this  process  left  behind  and 
the  serum  and  fibrin  passing  through  together,  the  fibrin  forms  a 
coagulum*  to  itself.  The  proportion  of  fibrin  in  the  human  subject 
to  the  entire  mass  of  blood  would  seem  to  be  very  small,  as  in  the 
experiments  of  Lecanu  he  found  fibrin,  when  dried,  to  form  from 
about  one  and  a third  to  seven  parts,  in  one  thousand. 

In  a spontaneous  coagulation  the  fibrin  attaches  itself  to  the  red 
globules  and  is  found  with  them,  while  the  serum  separates  and  is 
squeezed  out. 

So  long  as  it  continues  to  circulate,  or  while  it  is  still  flowing 
from  an  opened  vessel,  the  blood  has,  to  common  inspection,  the 
appearance  of  a homogenous  fluid  ; yet,  after  it  has  been  drawn  a 
few  minutes,  and  permitted  to  remain  at  rest,  it  assumes  a thick  ge- 
latinous condition,  expressed  by  the  term  coagulation,  and  by  which 
it  ceases  to  be  any  longer  fluid.  The  coagulation  begins  on  the  sur- 
face of  the  mass,  and  by  a thin  pellicle,  which  shows  itself  in  three 
or  four  minutes  ; commonly  at  the  end  of  twenty  minutes  the  coagu- 
lation is  complete  throughout,  but  this  rule  varies  according  to  the 
state  of  the  body  at  the  moment ; and  the  coagulation  is  more  pro- 
tracted when  the  quantity  of  blood  is  large  and  has  been  drawn 
through  a large  orifice,  than  where  it  is  small,  and  has  been  evacu- 
ated through  a small  orifice.  This  change  has  scarcely  taken  place, 
when  a spontaneous  separation  follows,  whereby  it  is  resolved  into 
the  watery  part,  or  Serum,  and  into  a thick  condensed  mass  called 
Cruor  or  Crassamentum.  The  serum  first  shows  itself  on  the  sur- 


* Physiology,  p.  124. 


208 


CIRCULATORY  SYSTEM. 


face  of  the  coagulum,  in  small  drops,  which  quickly  increasing  in 
number  and  size,  finally  run  together,  and  form  a mass  of  fluid  ex- 
ceeding considerably  that  of  the  crassamentum.  The  separation  into 
serum  and  crassamentum,  though  sufficiently  evident  after  a few 
hours,  yet  requires  some  days  for  its  complete  accomplishment ; for 
the  coagulum  still  continuing  to  contract,  expels  more  and  more  of 
the  serum. 

The  peculiar  complexion  of  the  blood  depends  upon  the  red  glo- 
bules. They  do  not  seem  to  be  an  indispensable  constituent,  as 
many  animals  are  entirely  deprived  of  them,  and  such  as  naturally 
are  possessed  of  them,  may  have  their  quantity  very  much  reduced 
by  repeated  bleedings.  The  colouring  matter  is  generally  an  in- 
gredient of  the  crassamentum,  so  that  the  whole  of  the  latter  has  a 
red  appearance  ; yet  there  are  some  conditions  of  the  body  in  which 
a spontaneous  separation  of  it  takes  place,  more  or  less  completely. 
For  example,  in  inflammatory  diseases  the  blood  does  not  coagulate 
so  soon  as  in  health  ; and  the  red  globules,  from  being  naturally 
heavier  than  the  other  constituents  of  the  crassamentum,  subside  to 
its  bottom  and  leave  it  of  a white  semi-transparent  colour.  It  is 
this  white  part  upon  which  depends  the  whole  property  of  coagu- 
lating, and  which  has  been  called  coagulating  lymph,  or  fibrin.  We 
have,  therefore,  three  constituents  of  blood  manifested  by  its  own 
spontaneous  changes ; the  Serum,  the  Red  globules,  and  the  Coagu- 
lating lymph. 

As  in  inflammation  the  red  particles  subside  to  the  bottom  before 
the  coagulation  of  the  fibrin  begins,  the  fibrin  is  seen  more  largely 
on  the  surface  of  the  clot,  and  by  a strong  contraction  in  coagulating 
draws  the  top  of  the  clot  into  the  form  of  a saucer.  There  is,  how- 
ever, always  a little  fibrin  left  throughout  the  clot,  and  holding  the 
red  particles  together;  with  the  exception  of  a few  which  maybe 
found  at  the  bottom  of  the  vessel,  perfectly  untrammelled  by  it.  It 
was  ascertained  by  Sir  C.  Scudamore  that  inflammatory  blood  con- 
tained more  fibrin  than  healthy  blood. 

Coagulation,  contrary  to  popular  opinion,  is  not  assisted  by  cold, 
but  rather  retarded  by  it : heat  assists  it.*  If  the  heat  be  raised  to 
120°,  blood  will  coagulate  five  minutes  sooner  than  if  left  at  its  na- 
tural standard,  and  even  sooner  than  if  its  temperature  be  reduced 
to  50°.  If  blood  be  frozen  quickly,  before  it  has  time  to  coagulate, 


* Hunter  on  the  blood.  Hewson. 


SERUM  OF  THE  BLOOD. 


209 


on  being  thawed  it  returns  to  the  fluid  state,  and  will  coagulate  after- 
wards. The  contact  of  air  does  not  produce  coagulation.  The  late 
Dr.  Physick,  in  order  to  ascertain  this  point  conclusively,  took  a glass 
tube,  which  had  a stop-cock  at  each  end,  and  attached  one  of  its  ends 
to  the  vein  of  a dog.  A current  of  blood  was  then  conducted  through 
the  tube,  and  while  it  was  flowing,  the  far  stop-cock  was  closed,  and 
immediately  afterwards  the  other ; thus,  a column  of  blood  was  ob- 
tained which  had  not  touched  the  air.  After  permitting  it  to  remain 
a proper  time,  the  tube  was  broken  asunder,  and  the  blood  found 
coagulated  as  usual.  Rest  is  not  indispensable  to  the  process,  for 
blood,  if  shaken  in  a vial,  will  still  coagulate.  The  division  of  the 
blood  into  small  masses  expedites  coagulation.  Therefore  when  it 
flows  slowly  from  the  blood  vessels,  falls  from  some  height,  or  runs 
for  a distance  over  the  surface  of  a dish,  it  coagulates  sooner  than 
under  opposite  circumstances.  The  latter  are  then  auxiliary  to  the 
blood  manifesting  the  sizy  coat,  one  of  the  concomitants  of  inflam- 
mation ; because  if  the  coagulation  be  very  rapid,  it  will  prevent  the 
constituents  of  the  crassamentum  from  separating  from  one  another, 
by  entangling  the  red  globules,  in  the  coagulating  lymph. 

After  death  the  blood  is  coagulated  in  the  veins,  though  not  so 
perfectly  or  generally  as  is  supposed,  for  there  are  no  subjects 
which  do  not  bleed  from  their  large  veins,  when  the  latter  are 
opened. 

The  coagulation  of  the  blood  is  sometimes  delayed  for  many 
hours  after  death.  I have  in  examining  the  head  of  a patient 
who  died  of  phthisis  pulmonalis  found  the  blood  which  came  from 
the  jugular  veins,  in  a thin  fluid  state  and  of  a bright  Vermillion 
colour ; and  upon  being  spread  out  on  a plane  surface  it  coagu- 
lated like  recent  blood. 

There  are  many  modes  of  death  which  prevent  entirely  the  coagu- 
lation of  the  blood  in  the  vessels,  for  example,  where  life  is  destroyed 
by  a paroxysm  of  excessive  anger;  by  electricity  ; by  lightning;  by 
a blow  upon  the  stomach ; by  certain  fevers  of  a typhoid  character. 
Many  chemical  articles  prevent  its  coagulation  on  being  mixed 
with  it. 


SECT.  I. — OF  THE  SERUlI  OF  THE  BLOOD. 

Serum  is  common  to  the  blood  of  all  animals,  and  is  considered, 
by  Mr.  Hunter,  to  be  more  abundant  in  such  as  have  red  globules. 

Vol.  II.— 19 


210 


CIRCULATORY  SYSTEM. 


It  is,  generally,  of  a lighter  specific  gravity  than  the  crassamentum. 

I have,  however,  often  seen  the  latter  floating  in  it,  which  shows  the 
contrary  in  some  instances.  Though  its  separation  commonly  de- 
pends upon  the  coagulation  of  the  latter,  yet  that  process  is  not  in- 
dispensably necessary,  as  was  once  witnessed,  by  Mr.  Hunter,  in  a 
lady,  in  whom  the  serum  was  disengaged  from  the  crassamentum, 
while  the  latter  was  yet  in  a fluid  state.  The  phenomena  of  dropsy, 
also,  prove  the  same  point. 

Serum  though  very  fluid,  is  not  so  much  so  as  water.  It  is  of  a 
light  yellow  or  straw  colour,  varying,  somewhat,  in  different  subjects. 
It  contains  a large  quantity,  about  eight  per  cent.,  of  albumen,  or 
matter  resembling  the  white  of  an  egg.  It  also  consists  of  water, 
about  ninety  per  cent.;  of  soda  uncombined,  and  of  several  of  the 
salts  of  soda,  the  presence  of  which  may  be  manifested  in  several 
ways.  For  example,  when  exposed  to  a heat  of  140  degrees  of 
Fahrenheit,  it  becomes  opaque,  and  at  160  or  165  coagulates  firmly. 
During  this  process,  a great  deal  of  air  is  disengaged  from  it.  It  is 
also  coagulated  by  spirits  of  wine,  by  all  the  mineral  acids,  by  cor- 
rosive sublimate,  and  by  many  other  articles.  They  all  prove  the 
presence  of  albumen.  Mr.  Brande  considers  the  albumen  as  an 
albuminate  of  soda,  and  that  its  fluidity  depends  on  the  excess  of 
soda ; when,  therefore,  the  latter  is  removed  or  neutralized  by  an 
acid,  the  albumen  coagulates.  Under  the  action  of  the  Galvanic 
pile,  like  the  influence  of  heat,  the  soda  produces  mucus,  by  blend- 
ing with  a part  of  the  albumen  ; and  the  remainder  of  the  latter,  not 
being  able  to  retain  its  fluidity  after  the  abduction  of  the  soda, 
coagulates. 

This  mucus  or  serosity  is,  probably,  the  part  which  Mr.  Hunter 
speaks  of  as  retaining  its  fluidity  when  other  portions  of  the  serum 
are  coagulated  by  heat.  It  is  observed  in  meat  either  roasted  or 
boiled,  and  comes  from  it  as  a thin,  limpid  fluid,  somewhat  tinged 
with  the  red  globules.  The  older  the  animal  is,  the  greater  is  its 
comparative  quantity : in  lamb,  there  is  scarcely  any  of  it,  whereas, 
in  mutton  five  or  six  years  old,  it  is  abundant ; the  same  rule  seems 
to  hold  in  regard  to  the  human  subject.  This  serosity,  or  mucus, 
is  coagulable  by  Goulard’s  extract.* 

The  serum  is  not  always  transparent,  but  sometimes  wheyish  and 
thin : when  it  settles,  it  often  throws  up  a white  scum  like  cream  and 
called  Seroline.  This  more  frequently  occurs  in  pregnant  women, 


* Hunter,  loc.  cit. 


COAGULATING  LYMPH  OF  THE  BL'OOD. 


211 


though  it  is  not  confined  exclusively  to  either  sex,  or  to  any  known 
condition  of  body.  The  specific  gravity  of  the  globules  composing 
this  seroline  varies ; for  though  it  generally  floats  on  the  surface  of  * 
the  serum,  it  does  not  always:  it  also  sometimes  swims,  and,  on 
other  occasions,  sinks  in  water.  It  has  been  erroneously  considered 
as  chyle  not  yet  assimilated,  or  as  absorbed  fat  or  oil.  It  is,  proba- 
bly, this  substance  which  presents  itself  under  the  form  of  micro- 
scopic globules  in  the  coagulum  of  serum ; and,  when  serum  has  been 
kept  for  several  days,  is  deposited  in  the  form  of  globules  at  its 
bottom.  These  globules  present  a singular  motion  of  ascent  and 
descent  in  the  serum  ; upon  the  application  of  heat  to  it  by  holding 
in  the  hand. 

The  presence  of  soda  uncombined  in  the  serum,  is  readily  ascer- 
tained by  an  infusion  of  red  cabbage,  (Brassica  oleracea,)  or  the  juice 
of  the  flag,  ( Iris  versicolor ,)  which  are  both  made  green  by  it.  Sul- 
phur combined  with  ammonia,  is  also  found  in  it.  Owing  to  the 
presence  of  sulphur,  serum  has  the  effect  of  blackening  silver  when 
left  in  it,  and  also  has  its  power  of  dissolving  the  oxydes  of  mercury, 
iron,  copper,  and  other  metallic  preparations. 

The  serum  contains  a portion  of  fatty  matter  allied  to  the  same 
substance  in  other  parts  of  the  body,  and  which  may  be  extracted 
with  ether.  It  also  contains  animal  principles,  whose  general  de- 
signation is  that  of  extractive  matter,  and  some  of  the  ingredients  of 
which  are  lactic  acid  and  osmazome.  They  are  believed  by  Ber- 
zelius to  be  the  effete  parts  derived  from  the  continual  decomposition 
of  the  body,  and  which  are  conveyed  away  through  the  excretions. 
There  are  some  other  salts  besides  those  mentioned  which  are  found 
in  serum.* 

The  serum  has  a specific  gravity  in  health  of  about  1030,  and  con- 
tains about  9J  per  cent,  of  solid  matter  including  the  albumen — the 
seroline  and  the  mineral  constituents. 


SECT.  II. — OF  THE  FIBRINE  OR,  COAGULATING  LYMPH  OF  THE 

BLOOD. 

Coagulating  lymph,  or  fibrine,  when  circumstances  are  suitable 
lor  collecting  it  free  from  the  red  globules,  offers  the  appearance  of  a 


* See  Henle,  Anat.  Gen.  t.  i.  p.  483. 


212 


CIRCULATORY  SYSTEM. 


semitransparent  body  of  a very  light  drab  colour  ; it  is  elastic  and 
strong,  and  when  subjected  to  the  microscope,  has  the  appearance 
*of  muscular  fibres,  by  being  composed  of  colourless  globules.  Like 
muscle,  it  also,  when  macerated  in  water,  resolves  itself  into  those 
globules  before  it  putrefies. 

If  the  blood,  while  flowing  from  an  animal,  be  collected,  and,  at 
the  same  moment,  stirred  around  and  around  with  a rough  stick,  the 
fibrine  will  gather  upon  the  latter  in  a fibrous  form,  so  as  to  resemble 
a mass  of  entangled  and  knotted  packthread.  The  fibrine  may  be 
afterwards  washed  almost  white,  and,  at  any  rate,  so  as  to  clear  it 
entirely  from  the  red  globules. 

The  fibrine,  when  dried,  loses  greatly  in  its  bulk  and  weight,  by 
the  evaporation  of  the  serum  from  it,  so  that  the  proportion  which 
it  seems  to  bear  to  the  whole  mass  ofblood,  is  much  less  considera- 
ble than  one  would  suppose,  from  seeing  it  in  the  simple  coagulated 
state. 

The  coagulating  lymph  of  the  blood  being  common,  probably  to 
all  animals,  while  the  red  particles  are  not,  wre  must  suppose  it  from 
this  alone  to  be  the  most  essential  part ; and,  as  we  find  it  capable 
of  undergoing,  in  certain  circumstances,  spontaneous  changes,  which 
are  necessary  to  the  growffh,  continuance,  and  preservation  of  the 
animal ; while  to  the  other  parts  we  cannot  assign  any  such  uses  ; we 
have  still  more  reason  to  suppose  it  the  most  essential  part  of  the- 
blood  in  every  animal.”* 

In  examining  a drop  of  blood  with  a deep  object  glass,  there  is 
apparent  in  the  field  of  vision  one  or  two  white  globules,  the  average 
diameter  of  which  is  about  j-gols  of  an  inch.  They  are  either  smooth 
or  granulated  on  the  surface,  semitransparent  and  spherical,  or  nearly 
so.  They  differ  from  the  blood  discs,  or  red  globules,  in  being 
nearly  the  same  in  all  animals,  they  are  more  obscure  in  the  human 
subject  and  mammalia,  but  are  very  distinct  in  reptiles,  birds,  and 
fishes.  They  wrere  first  seen  by  Spallanzani  in  the  Salamander,  and 
then  noticed  in  the  blood  of  Mammalia,  by  M.  Mandl,  a few  years 
ago  ; they  are  considered  by  the  latter  as  produced  by  a coagulation 
of  fibrin,  and,  as  identical  with  the  globules  of  pus  and  mucus.  By 
Mr.  Gulliverf  they  are  called  nucleated  cells  or  organic  germs  of 
fibrin:  he  is,  however,  doubtful  of  their  perfect  identity  with  the 
particles  quoted  by  Mr.  Mandl. 

* Hunter,  loe.  cit. 

f Appendix  to  Gerber’s  Gen.  Anat.,  p.  14. 


RED  GLOBULES  OF  THE  BLOOD. 


213 


Besides  the  above,  Mr.  Gulliver  has  seen  a white  matter  existing 
in  abundance  in  the  form  of  spherules,  of  from  4,5^  to  t-ttt  of  an 
inch.  The  animals  in  whom  it  was  witnessed  had  died  chiefly  of 
tubercular  phthisis,  and  he,  therefore,  is  inclined  to  think  this  a pa- 
thological appearance. 

Besides  milky  serum,  which  is  sometimes  found  in  the  blood  after 
a repast,  corpuscles  of  a peculiar  kind  have  been  noticed  in  the 
splenic  and  supra  renal  veins,  which  are  supposed  to  come  from  the 
spleen  and  from  the  capsulse  renales. 


SECT.  III. — OF  THE  RED  GLOBULES  OF  THE  BLOOD.* * * § 

The  impression  at  the  present  day  in  regard  to  the  red  globules, 
or  Blood  discs,  as  they  are  also  called,  is  that  they  are  flattened  bodies 
of  a circular  shape  and  having  a thickness  from  a fourth  to  a half  of 
their  breadth.  To  see  them  of  this  figure,  they  should  be  ex- 
amined in  fresh  serum,  a weak  solution  of  common  salt,  or  in  thin 
syrup  ; if  water  alone  be  used  they  contract  into  a spheroidal  shape. 
In  birds,  reptiles,  and  fishes  they  are  elliptical. 

In  the  lower  orders  of  animals  the  disc  appears  to  have  a central 
nucleus,  which  projects  in  a rounded  form  above  the  general  surface 
of  the  disc.  In  the  siren,  according  to  Professor  Owen,  the  disc 
consists  of  from  twenty  to  thirty  spherical  granules.  But  very  great 
doubt  exists  in  regard  to  the  nucleus  in  man  and  the  mammalia  gene-' 
rally.  Authority  of  the  highest  kind  may  be  quoted  for  either  opi- 
nion. Mullerf  says  he  has  seen  it,  Carpenter  is  inclined  to  admit 
it,  Gulliver J denies,  and  Wagner  who  once  admitted  it,  now  holds 
it  as  uncertain,  Henle§  says,  that  drying  renders  the  nuclei  of' 
the  corpuscles  of  the  blood  very  obvious,  and  that  in  calcining  them, 
the  wrecks  of  the  nucleus  and  feeble  traces  of  the  envelope,  are  dis- 
cernible. This  is  the  result  of  his  observations  on  the  lower  orders 
of  vertebrata,  but  in  the  human  subject  and  mammalia,  lie  evidently 
disinclines  to  the  opinion  of  nuclei  existing  in  the  blood  discs.  He 
says,  in  one  place  that  the  pretended  nucleus  is  only  the  depressed 

* Anat.  Atlas,  Figs.  434,  435. 

f Page  115. 

Appendix  to  Gerber,  p.  15. 

§ Encyclop.  Anat.,  vol.  vi.,  p.  466,  Paris,  1843., 

19* 


214 


CIRCULATORY  SYSTEM. 


centre  of  the  disc,  and  in  another  place,  he  says,  that  in  all  his  ex- 
periments, it  has  scarcely  ever  occurred  to  him  to  see  any  trace  of 
nucleus. — Numerous  opinions  for  and  against  may  thus  be  cited,  and 
while  the  question  is  agitated  by  the  best  observers,  others  may  very 
properly  await  their  decision. 

Under  common  observation  the  light  transmitted  through  the 
centre  of  the  blood  discs  is  more  intense  than  elsewhere,  which  gives 
to  them  the  appearance  of  being  perforated  or  annular. 

By  many,  each  blood  disc  is  considered,  notwithstanding  the  diffi- 
culties of  determining  such  minute  points  of  structure  in  the  human 
body,  to  consist  in  a capsule,  a contained  matter,  and  a nucleus  in 
its  centre.  The  advocates  of  this  opinion,  also  view  it  as  a de- 
termined fact,  that  the  blood  discs  conform  in  their  general  character 
with  the  isolated  cells,  which  constitute  the  whole  of  the  simplest 
plants,  each  having  an  independent  life  of  its  own. 

The  improvements  of  the  compound  microscope  have  enabled  us 
to  determine  with  accuracy,  the  diameter  of  the  blood  discs  or  red 
globules.  It  appears  now  that  there  is  no  absolute  or  uniform  size 
to  them  in  the  same  mass  of  blood,  but  that  they  vary  much  in  this 
respect,  some  being  about  --u1—  of  an  inch,  and  others  about  the 
■3  J . Other  animals  than  man  present  them  of  a larger  or  smaller 
size,  thus  in  the  fish  called  Squalus  Squatina,  they  are  about  the 
— t — of  an  inch,  whereas,  in  the  cat  they  measure  about  — J — . 

The  different  magnitudes  in  man  are  supposed  to  be  accounted 
for  by  admitting  them  as  cells  in  various  stages  of  growth  and  evo- 
ution.  Their  size  has  no  relation  to  the  magnitude  of  the  animal, 
lor  in  the  Mouse  they  have  three  times  the  diameter  of  those  of  the 
Musk  deer. 

The  proportion  of  blood-discs  varies  very  much  in  different  persons : 
the  average  is  about  140  in  one  thousand  parts  of  blood  in  the  male, 
but  it  may  go  to  186  or  descend  to  110  without  ill  health.  In  the 
female  the  average  is  about  112  in  the  thousand,  but  it  may  fall  to 
71  or  rise  to  167  in  common  health.  In  chlorosis  it  has  been  found 
as  low  as  27,  and  not  unfrequently  is  at  from  40  to  50  parts  in  the 
thousand.* 

The  blood  corpuscles,  or  blood  discs,  are  larger  in  the  embryo 
than  in  the  adult,  Mr.  Prevost  has  seen  that  they  were  in  the  foetal 
goat  twice  the  size  of  such  as  belonged  to  the  maternal.  Mr.  Barry 

* Carpenter’s  Elem.  of  Physiol.  p.  309. 


RED  GLOBULES  OF  THE  BLOOD. 


215 


asserts,  that  the  germinal  state  of  every  tissue  is  that  of  corpuscles, 
having  the  same  appearance  with  the  blood  corpuscles,  and  Mr. 
G ulliver,  that  they  are  much  more  abundant  in  inflammatory  diseases 
than  in  health. 

It  has  been  already  observed  that  the  red  globules  are  the  heaviest 
part  of  the  mass  of  blood,  and  are,  therefore,  always  disposed  to 
subside  to  the  bottom  of  the  crassamentum,  though  from  the  quick 
coagulation  of  the  latter,  they  can  seldom  do  it  fully  before  they 
become  entangled  in  it,  and  thereby  fixed  to  a certain  place.  They 
do  not  invariably  retain  their  form,  but  are  readily  dissolved  in 
water.  They  are,  of  course,  insoluble  in  serum.  Urine  does  not 
dissolve  them;  neither  does  a solution  of  muriate  of  soda,  of  sal 
ammoniac,  epsom  salts,  nitre,  diluted  sulphuric  or  muriatic  acid : 
the  latter,  however,  deprives  them  of  colour. 

The  solution  of  red  globules  in  water  is  manifested  by  the  mixture 
becoming  of  a fine  transparent  red,  and  the  process  takes  place 
almost  immediately.  On  the  contrary,  when  the  globules  refuse  to 
be  dissolved,  a muddy  mixture  is  formed.  When  they  are  dried  in 
serum,  and  afterwards  soaked  again  in  it,  they  do  not  resume  the 
regular  form.  They  have  more  substance  than  the  coagulating 
lymph,  for  they  do  not  lose  so  much  of  their  bulk  by  drying. 

The  analysis  of  the  blood  corpuscles  presents  two  proximate  prin- 
ciples, hoematosin  and  globulin.  The  first  amounts  to  about  or 
is  of  the  mass  when  the  globules  are  dried,  and  when  burned,  it 
yields  a quantity  of  peroxide  of  iron. 

The  colouring  ingredient  of  the  red  globule,  is  commonly  con- 
sidered to  be  the  peroxide  of  Iron.  In  some  recent  experiments  of 
Mr.  Scherer,  this  belief  has  been  assailed,  if  not  invalidated,  by  his 
observing,  that  though  the  iron  be  removed,  yet  alcohol  can  be 
made  intensely  red  by  boiling  in  it  the  globules  left  after  such  ex- 
traction. 

“ It  is  difficult  to  determine  by  what  means  the  iron,  or  the  sul- 
phur, or  the  elementary  principles  of  the  calcarious  earths,  obtain  an 
existence  in  the  blood.  If  these  materials  were  equally  diffused 
throughout  the  surface  of  the  earth,  we  might  easily  conceive  that 
they  were  introduced  through  the  medium  of  food.  But  as  this  is 
not  the  case,  as  some  regions,  like  New  South  Wales,  at  least,  on 
this  side  the  Blue  Mountains,  contain  no  limestone  whatever,  and 
others,  no  iron  or  sulphur,  while  all  these  are  capable  of  being  ob- 
tained apparently  as  freely  from  the  blood  of  the  inhabitants  of  such 


216 


CIRCULATORY  SYSTEM. 


regions,  as  from  that  of  those  who  live  in  quarters  where  such  ma- 
terials enter  largely  into  the  natural  products  of  the  soil:  it  is,  per- 
haps, most  reasonable  to  conclude  that  they  are  generated  in  the 
laboratory  of  the  animal  system  itself,  by  the  all-controlling  in- 
fluence of  the  living  principle.”* 

The  red  globules,  according  to  the  opinion  of  Mr.  Hunter,  from 
not  being  pushed  into  the  extreme  arteries,  where  the  coagulating 
lymph  reaches,  and  from  not  being  found  in  all  animals,  do  not  con- 
tribute to  the  growth  and  to  the  repair  of  the  system.  But  they  seem 
to  be  connected  with  strength,  in  such  animals  as  have  them,  as  the 
strength  acquired  by  exercise  increases  their  proportion  and  occa- 
sions them  to  be  carried  abundantly  into  parts  which  previously,  from 
a debilitated  state,  received  them  but  partially  if  at  all.  This  fact 
is  wrell  known  to  graziers,  who  keep  their  quantity  in  certain  animals, 
as  veal,  reduced  by  quietude  and  frequent  bleeding. 

Their  source  is  not  understood,  though  many  conjectures  on  the 
subject  have  been  hazarded. 

Leeuwrenhoeck  asserted,  that  they  had  the  power  of  self-repro- 
duction, and  this  statement  has  received  additional  confirmation  by 
the  observations  of  Mr.  Barry. f According  to  him  the  propagation 
takes  place  by  the  parent  globule  splitting  into  about  six  others,  the 
development  starting  from  its  nucleus.  As  there  is  a continual  de- 
composition going  on,  each  disc  or  cell  has  a definite  period  of 
existence,  and  while  some  are  dying  others  are  coming  into  exis- 
tence. 

Mr.  Hunter’s  opinion  was,  that  they  do  not  appear  to  be  formed: 
in  those  parts  of  the  blood  already  produced,  but  rather  to  rise  up 
in  the  surrounding  parts : as,  in  the  incubated  egg,  they  exist  in  the 
form  of  a zone,  composed  of  dots,  previously  to  the  formation  of 
vessels. 

The  above  sentiments  of  a very  celebrated  man,  it  may  be  well 
enough  to  preserve,  though  they  seem  to  be  in  contradiction  wfith 
present  views,  except  the  appearance  at  first  in  the  incubated  egg. 

The  analysis  of  Mr.  Lecanu,  in  regard  to  all  the  elements,  organic, 
and  inorganic,  entering  into  the  composition  of  the  blood,  is  regarded 
as  having  a high  claim  to  confidence.  The  blood  wTas  obtained  in 
twTo  parcels,  each  from  a stout  healthy  man: 

* Good,  Stud,  of  Med. 
f Phil.  Trans.  1840,  and  1841. 


RED  GLOBULES  OF  THE 

BLOOD. 

217 

Water 

780.145 

785.590 

Fibrin 

2.100 

3.565 

Albumen 

65.090 

69.415 

Colouring  matter,  (globules)  . 

133.000 

119.626 

Fatty  crystallizable  matter 

2.430 

4.300 

Oily  matter 

1.310 

2.270 

Extractive  matter,  soluble  in  water 

1 .790 

1.920 

and  alcohol  ‘ 

Albumen  combined  with  soda. 

1.265 

2.010 

Chloride  of  Sodium 
u potassium 

Carbonates  4 of  Potash  and  Soda 
Phosphates  > “ “ 

Sulphates  ) “ “ 

\ 

8.370 

7.304 

Carbonates,  Lime,  and  Magnesia  ) 

Phosphates,  Lime,  Magnes.  and  Iron  > 

2.100 

1.414 

Peroxide  of  Iron  ) 

Loss  . 

* 

2.400 

1.000.000 

2.886 

1.000.000 

Denis  found  the  proportion  of  water  in  man’s  blood  to  vary  from 
805  to  732  in  a thousand  parts,  and  in  woman  from  848  to  750. 
According  to  Lecanu,  the  quantity  of  water  bears  no  determined 
relation  to  the  period  of  life  ; Denis,  however,  found  it  more  abun- 
dant in  children,  and  in  aged  persons.  In  sanguine  temperaments 
the  blood  has  less  water  in  it  than  in  lymphatic. 

The  proportion  of  albumen  varies  from  57.890  to  78.270,  and  is 
about  the  same  in  the  two  sexes.  The  crassamentum  consisting  of 
the  red  globules  and  of  fibrin,  varies  from  about  68.349,  to  148.450, 
and  in  men  it  is  more  abundant  than  in  women,  in  the  proportion  of 
32.980  parts  in  the  thousand.* 

* For  very  erudite  and  interesting  Essays  on  the  blood  in  regard  to  its  cor- 
puscles, liquor  sanguinis  or  plasma,  quantitative  analysis,  development,  re- 
generation, and  other  points  connected  with  it,  a full  account  of  which  would 
be  too  long  for  the  present  work ; the  reader  is  referred  to  the  writings  of 
Hewson  and  Hunter,  in  the  last  century.  Henle’s  Gen.  Anat.  p.  457,  et 
seq.  Paris,  1843.  Muller’s  Physiology,  by  Baly,  p.  109,  et  seq.  vol.  i.  London, 
1842.  Principles  of  Human  Physiology,  by  W.  B.  Carpenter,  p.  464,  et 
seq.  London,  1842.  Wagner’s  Elements  of  Physiology,  by  Willis,  p.  230. 
London,  1842.  Animal  Chemistry  by  Dr.  J.  F.  Simon.  Phila.  1846. 


' 


1 


X 


BOOK  VIII 


FART  IS. 

OF  THE  SPECIAL  AMATOIY  OF  THE  CIRCULATORY  SYSTEM. 
CHAPTER,  I. 

Of  tlie  Heart  and  Pericardium.* 

The  Heart,  (Cor,)  the  centre  of  the  circulation,  is  situated  in  the 
thorax,  between  the  sternum  and  the  spine ; being  bounded  on  its 
sides  by  the  lungs,  and  below  by  the  tendinous  centre  of  the  dia- 
phragm. It  is  a hollow  muscular  organ. 

The  heart  is  of  a conoidal  shape,  but  flattened  on  the  surface 
which  lies  upon  the  diaphragm.  This  flat  surface  is  on  a horizontal 
line  with  the  lower  end  of  the  second  bone  of  the  sternum  ; the  base 
of  the  cone  is  towards  the  vertebrae,  and  looks  obliquely  backwards 
to  the  right  side,  while  the  apex  is  about  the  junction  of  the  left  fifth 
rib  with  its  cartilage.  Its  common  weight  is  about  six  ounces.  Its 
greatest  length,  to  wit,  that  from  the  apex  to  the  base,  is  about 
five  and  a half  inches,  four  of  which  are  taken  up  by  the  ventricles  : 
its  base  is  about  three  and  a half  inches  in  diameter. 

The  heart  is  divided  into  four  cavities ; twTo  auricles  and  two  ven- 
tricles : the  places  where  the  partitions  are  placed  between  these 
cavities  are  marked  on  the  surface  of  the  heart  by  fissures  or  depres- 
sions, sufficiently  distinct  to  be  immediately  recognised.  The  two 
auricles  form  the  base  of  the  heart,  the  ventricles  constitute  its  body, 
and  the  anterior  end  of  the  left  ventricle,  by  being  extended  somewhat 


* Anat.  Atlas,  Figs.  439  to  447,  inclusive. 


220 


CIRCULATORY  SYSTEM. 


beyond  the  right  forms  the  apex.  The  right  auricle  and  the  right 
ventricle,  are  the  two  cavities  which  are  nearest  to  the  right  side  of 
the  body,  while  the  left  auricle  and  the  left  ventricle  are  the  two 
cavities  nearest  to  the  left  side.  It  will,  however,  be  understood, 
from  the  general  observations  already  made,  that  the  relative  situa- 
tion of  these  cavities  is  such,  that  the  right  ones  are  in  front  of  the 
others,  and  present  obliquely  forwards  to  the  right  side,  while 
those  on  the  left  look  obliquely  backwards  to  the  left  side.  This 
position  of  the  heart  makes  it  encroach  more  upon  the  left  cavity  of 
the  thorax  than  it  does  upon  the  right ; from  which  cause  its  pulsations 
may  be  very  easily  distinguished  where  the  left  ribs  join  their  car- 
tilages, while  on  the  right  side  of  the  sternum  there  is  scarcely  ever 
a perceptible  pulsation.  Being  placed  between  the  right  and  the 
left  pleura,  in  the  mediastinum,  it  is  surrounded  by  its  own  proper 
capsule  called  the  Pericardium. 

The  Pericardium  is  covered  on  its  sides  by  the  Pleurae,  and  re- 
poses on  the  tendinous  centre  of  the  diaphragm,  to  which  it  adheres 
by  close  compact  cellular  substance,  particularly  at  its  periphery. 
When  the  latter  attachment  is  cut  through,  a separation  of  the  re- 
mainder is  easily  effected.  Behind,  the  pericardium  is  opposite  to 
the  bronchia  and  to  the  oesophagus. 

The  pericardium  does  not  adhere  to  the  heart,  except  at  the  base 
of  the  latter;  it  is,  therefore,  a loose  capsule  in,  by  far,  the  greater 
part  of  its  extent.  It  not  only  surrounds  the  heart,  but  also  the  roots 
of  the  large  arteries  and  veins  connected  with  it.  Thus,  it  includes 
the  aorta,  as  high  up  as  the  great  vessels  proceeding  from  its  arch  ; 
from  the  latter,  it  passes  to  the  trunk  of  the  pulmonary  artery,  and 
also  includes  it,  causing  the  aorta  and  the  pulmonary  artery  to  lie 
close  together.  The  posterior  face  of  these  vessels  is  not  covered 
so  high  up  as  the  anterior  face.  The  pericardium  also  invests  the 
descending  vena  cava  for  an  inch  above  its  junction  with  the  right 
auricle : it  likewise  invests  the  trunks  of  the  pulmonary  veins,  and 
tire  ascending  cava  as  it  rises  above  the  diaphragm.  The  pouches 
which  it  forms  at  the  base  of  the  heart,  in  passing  from  one  of  these 
vessels  to  another,  are  the  cornua  of  some  anatomists.  It  cannot  be 
considered  as  pierced  for  the  passage  of  these  vessels,  but  is  lost 
insensibly  on  their  parietes ; being  continued  into  the  cellular  cover- 
ing of  the  arteries,  in  accompanying  them  to  a great  distance.* 

* Sabatier,  Trait.  d’Anat.  vol.  ii.  p.  284. 


PERICARDIUM. 


221 


The  pericardium  is  a double  membrane,  or  consists  of  two  layers, 
an  internal  and  external  one.  The  external  membrane,  to  which 
the  preceding  description  is  especially  applicable,  resembles  strongly 
the  dura  mater,  but  is  thinner;  it  is,  therefore,  white,  semi-transpa- 
rent, fibrous,  and  inelastic.  Its  thickness  is  greater  on  the  sides, 
than  below  where  it  rests  upon  the  diaphragm;  or  above,  where  it 
goes  along  the  great  vessels : its  fibres  are  irregularly  disposed  and 
interwoven,  but  many  may  be  traced  longitudinally. 

The  Internal  layer  lines  the  external,  and  gives  the  polish  to  its' 
cardiac  surface ; it  is  then  conducted  along  the  surface  of  the  seve- 
ral vessels  that  have  been  mentioned,  to  the  heart,  over  the  whole 
of  which  it  is  spread,  and  adheres  to  it  by  cellular  substance,  fre- 
quently containing  much  adipose  matter:  it  also  causes  the  heart 
to  have  a smooth  shining  surface.  This  is  a very  delicate  thin 
serous  layer;  and  secretes  a fluid,  transparent  and  somewhat 
unctuous,  like  that  of  the  joints,  but  not  so  consistent ; which  lu- 
bricates the  surface  of  the  heart  and  permits  it  to  play  freely  within 
its  pericardium.  This  fluid,  in  a natural  state,  seldom  exceeds  a 
tea-spoonful,  though  two  ounces,  or  a little  more,  are  not  considered 
sufficient  evidence  of  a pathological  state  : its  augmentation  consti- 
tutes a dropsy. 

After  death,  we  find  the  pericardium  lying  loosely  around  the 
heart,  from  the  vacuity,  and  consequently  diminished  bulk  of  the 
latter;  but  while  the  circulation  is  going  on,  the  heart  fills  and 
distends  it.  A striking  resemblance  is  observable  between  the 
condition  of  the  pericardium  and  the  moveable  articulations.  Its 
external  layer  corresponds  with  the  strong  fibrous  capsule  that 
passes  from  one  bone  to  the  other ; while  the  internal  is  the  syno- 
vial bag,  which  scarcely  assists  in  the  strength  of  the  apparatus, 
but  secretes  a fluid  to  render  motion  easy. 

Several  instances  are  on  record  of  a total  absence  of  pericardium. 

The  Right  Auricle  {Auricula  Dextra , Anterior)  is  an  oblong  cu- 
boidal  cavity.  It  is  joined  at  its  posterior  superior  angle  by  the  de- 
scending vena  cava,  and  at  its  posterior  inferior  angle  by  the  ascend- 
ing vena  cava.  The  structure  of  the  auricle,  between  these  wet 
points,  seems  to  be  only  a continuation  of  that  of  the  veins.  These 
veins  enter  with  a direction  slightly  forwards,  so  that  their  columns 
of  blood  are  not  directly  opposed  to  each  Other.  In  front  of  this 
continuation  of  the  two  veins,  the  auricle  is  dilated  into  a pouch 
Vol.  II.— 20 


222 


CIRCULATORY  SYSTEM. 


called  its  Sinus:  the  upper  extremity  of  the  latter,  just  in  front  of 
the  descending  cava,  is  elongated  into  a process  with  indented 
edges,  and  has  some  general  resemblance  to  the  ear  of  an  animal, 
from  which  it  is  probable  that  the  term  Auricle  has  been  derived. 

The  exterior  surface  of  this  cavity  is  smooth  arid  uniform,  but 
its  internal  surface  is  varied  at  several  places.  About  midway  be- 
tween the  orifices  of  the  two  cavae  is  found  a transverse  prominence, 
the  Tuberculum  Loweri,  which  is  occasioned  by  the  continuous 
structure  of  the  veins  meeting  at  an  obtuse  angle.  This  cavity  is 
separated  from  the  left  auricle  only  by  a thin  septum,  which  is  com- 
mon to  the  two  auricles.  On  the  septum,  below  its  middle,  is  a 
superficial  circular  depression,  the  Fossa  Ovalis;  it  is  more  distinct 
above  than  below,  and  varies  much  in  its  dimensions.  It  is  sur- 
rounded by  an  elevated  margin,  composed  of  muscular  fibres,  and 
called  its  Annulus,  or  the  Isthmus  of  Vieussens.  The  septum  of  the 
auricles  is  thinner  at  the  fossa  ovalis  than  elsewhere,  and  is  fre- 
quently perforated  by  one  or  more  foramina.  I have,  in  several 
instances,  seen  a hole  there,  large  enough  to  transmit  the  finger. 
On  such  occasions,  from  the  valvular  arrangement  of  the  opening, 
it  is  probable  that  the  blood  of  the  two  auricles  is  still  kept  distinct. 
The  fossa  ovalis  always  presents  this  foramen  in  the  foetal  state. 

Just  below  the  fossa  ovalis  is  found  the  Eustachian  valve,  con- 
sisting in  a duplication  of  the  lining  membrane  of  the  auricle.  It  is 
crescentic,  but  varies  much  in  its  dimensions  and  shape.  Its  left 
extremity  commences  at  the  left  inferior  margin  of  the  annulus 
ovalis ; it  then  extends  itself  along  the  front  of  the  orifice  of  the  as- 
cending cava,  where  the  latter  is  connected  with  the  auricle,  but 
never  to  an  extent  sufficient  to  arrest  the  circulation  there.  Some- 
times it  is  reticulated  at  its  margin,  and  half  an  inch  wide ; on  other 
occasions,  it  is  scarcely  developed.  Its  loose  edge  looks  upwards, 
and  to  the  right  side.  Its  office  in  the  foetus  is  clearly,  according 
to  the  opinion  of  Sabatier,  to  direct  the  blood  of  the  ascending  cava 
through  the  foramen  ovale.  In  the  adult,  it  may,  on  the  general 
principle  of  venous  valves,  oppose  itself  to  the  introduction  of  re- 
fluent blood  into  the  ascending  cava;  but  this  office  cannot  be  very 
exactly  performed,  as  the  valve  is  frequently  scarcely  visible  at  that 
age. 

At  the  lower  part  of  the  right  auricle,  just  to  the  left  of  the 
Eustachian  valve  and  very  near  it,  is  the  orifice  of  the  large  coro- 


THE  HEART. 


223 


nary  vein  of  the  heart:  it  is  protected  by  a small  semi-lunar  valve, 
( Valvula  Thebesii ,)  formed  also  by  a duplication  of  the  lining  mem- 
brane of  the  auricle.  This  orifice  will  admit  a quill  of  common  size 
very  readily. 

At  the  anterior  semicircumference  of  the  descending  vena  cava, 
there  is  an  oblique  fasciculus  of  muscular  fibre,  with  which  the  ad- 
joining musculi  pectinati  are  connected,  and  which  in  its  contrac- 
tion will  answer,  to  a limited  degree,  as  a valve  or  barrier,  in  pre- 
venting the  reflux  of  blood  from  the  auricle  into  the  cava.  A smaller 
fasciculus  of  muscular  matter  also  exists  along  the  base  of  the  Eu- 
stachian valve,  and  will  execute  the  same  office  for  the  ascending 
cava.  The  office  however  of  neither  is  perfect,  but  limited  to  a 
partial  state  of  occlusion. 

Between  the  right  auricle  and  ventricle  is  a round  hole,  of  more 
than  an  inch  in  diameter,  for  the  passage  of  the  blood  ; it  is  the 
Ostium  Venosum.  Its  margin,  on  the  auricular  side,  is  smooth 
and  rounded. 

The  parietes  of  the  right  auricle  are  formed  by  muscular  fibres. 
On  the  Sinus  these  fibres  are  collected  into  small  transverse  fasci- 
culi, called  Musculi  Pectinati,  from  their  resembling  the  teeth  of 
a comb.  These  fasciculi,  though  slightly  united  by  other  fibres, 
yet  leave  between  them  deep  interstices,  by  which  the  external 
and  the  internal  membrane  of  the  heart  come  into  contact.  The 
parietes  of  the  auricle  are  about  one  line  in  thickness.  Its  mus- 
cular structure  is  continued  for  a short  distance,  on  the  two  venae 
cavse.  There  are  several  orifices  of  small  veins  on  the  internal 
surface  of  this  cavity,  and  in  greater  abundance  around  the  fossa 
ovalis ; they  belong  to  the  system  of  coronary  vessels,  and  are  the 
foramina  Thebesii. 

The  Right  Ventricle  ( Ventriculus  Dexter , Anterior.)  The  general 
form  of  this  cavity,  which  receives  the  blood  from  the  right  auricle, 
is  that  of  a triangular  pyramid,  curved  somewhat  backwards,  and 
having  its  base  downwards.  It  forms  the  greater  part  of  the  ante- 
rior surface  of  the  heart,  and  is  about  three  lines  in  thickness.  It 
is  bounded  on  its  posterior  face  by  the  left  ventricle,  from  which  it 
is  completely  separated  by  a thick  septum. 

The  internal  surface  of  this  cavity  is  covered  by  muscular  fasciculi, 
of  very  irregular  shapes  and  dimensions,  designated  under  the  term 
ColumnEe  Carnese : some  of  the  latter  go  from  one  side  to  the 


224 


CIRCULATORY  SYSTEM. 


other ; others  contribute  to  the  mechanism  of  the  valvular  apparatus 
between  it  and  the  right  auricle  ; but  the  greater  portion  is  employed 
in  forming  a complicated  reticular  texture  over  the  internal  face  of 
the  ventricle.  Those  connected  with  the  valve  vary  from  four  to 
eight  in  number : they  are  rounded,  of  different  lengths  and  sizes, 
and  detach  from  their  projecting  extremities  several  small  rounded 
tendinous  chords,  ( Chorda  tendinece ,)  which  are  inserted  into  the 
floating  edge  of  the  valve.  These  chords  form  an  intertexture 
among  themselves. 

The  Valve,  between  the  ventricle  and  the  auricle,  consists  in  a 
duplicature  of  the  lining  membrane  of  the  ventricle,  arising  unin- 
terruptedly from  around  the  ostium  venosum,  at  the  left  margin, 
which  is  there  somewhat  tendinous.  This  valve  is  called  tire  Tri- 
cuspid, ( Valvula  Tricuspis,  Triglochis,)  because  its  loose  margin 
is  divided  into  three  points  or  processes.  One  of  these  points, 
which  is  at  the  anterior  external  margin  of  the  orifice,  is  much 
larger  than  the  o&er  two  and  more  distinct  in  its  boundaries. 
The  edges  of  these  processes  form  a sort  of  reticulated  work  along 
with  the  adjoining  ends  of  the  tendinous  chords : by  this  arrange- 
ment they  are  always  kept  expanded  and  in  the  cavity  of  the  ven- 
tricle. 

The  opening  for  the  pulmonary  artery  is  placed  above  the  ostium 
venosum ; at  this  point,  the  cavity  of  the  ventricle,  instead  of  being 
reticulated,  is  made  smooth,  for  the  more  ready  transmission  of 
blood.  The  orifice  of  the  pulmonary  artery  is  round,  and  about 
twelve  lines  in  diameter  ; it  is  furnished  with  three  valves,  called 
from  their  shape  Semi-lunar  or  Sigmoid.  Each  valve  is  a semi- 
circular plane,  formed  from  the  lining  membrane  of  the  artery,  and 
attached  to  the  latter  by  its  semi-circumference.  The  diameter  of 
the  plane  is  loose,  and,  instead  of  being  straight  has  each  semi- 
diameter of  a curved  or  festooned  shape : in  the  centre  of  its  edge 
is  a small  cartilaginous  body,  the  Corpuseulum  Aurantii,  which  when 
the  valve  is  thrown  down  by  the  reaction  of  the  artery,  comes  in 
contact  with  the  corresponding  bodies  of  the  other  valves,  so' that 
they  serve  as  mutual  abutments.  The  Corpuseulum  is  some- 
times scarcely  discernible.  Between  the  outer  face  of  each  valve 
and  the  artery  there  is  a pouch,  attended  with  a slight  dilatation  of 
the  artery,  and  called  the  Sinus  ValsalvEe.  Between  the  coats  of 
each  valve  there  is  an  additional  fibrous  substance,  for  the  purpose  of 
strengthening  it. 


THE  HEART. 


225 


The  Pulmonary  Artery,  immediately  after  its  origin,  goes  up- 
wards and  backwards  to  the  under  part  of  the  curvature  of  the  aorta, 
and  there  divides  into  two  trunks,  one  for  each  lung.  These  trunks 
separate  widely,  and  from  the  middle  of  their  fork  proceeds  a liga- 
mentous substance,  the  remains  of  the  Ductus  Arteriosus  of  the  foetus, 
to  the  aorta  posteriorly  to  the  origin  of  the  left  subclavian  artery. 
The  right  Pulmonary  artery  is  both  longer  and  larger  than  the  left, 
and  passing  transversely  behind  the  aorta  and  the  descending  cava, 
then  penetrates  the  substance  of  the  lung  to  be  distributed  as  men- 
tioned. The  left  pulmonary  artery  passes  to  the  lung  in  front  of  thp 
descending  aorta.  Though  the  pulmonary  artery  is  quite  as  large 
as  the  aorta,  its  parietes  are  thinner. 

The  Left  Auricle,  ( Auricula  Sinistra,  Posterior ,)  in  the  natural 
situation  of  the  heart,  is  concealed  by  the  right  auricle  and  the  ven- 
tricles. Its  figure  is  more  regularly  quadrangular,  or  square,  than 
that  of  the  right,  and  into  each  of  its  angles  is  introduced  a pul- 
monary vein,  there  being  two  on  each  side.  Sometimes,  however, 
the  latter  join  together  previously,  so  that  the  two  have  but  a com- 
mon orifice.  Its  tip,  or  ear -like  portion,  is  situated  at  the  left  side 
of  the  pulmonary  artery,  and  is  longer,  narrower,  more  crooked, 
and  more  notched  at  its  margins  than  the  corresponding  portion  of 
the  right  auricle. 

The  parietes  of  this  cavity  are  muscular,  and  somewhat  thicker 
than  those  of  the  right ; they  are  smooth  and  uniform,  both  exter- 
nally and  internally,  with  the  exception  of  its  appendix  or  ear-like 
portion,  in  which  the  musculi  pectinati  prevail.  The  term  Sinus 
Venosus  or  Sinus  Pulmonalis  of  anatomists,  only  means  that  part  of 
the  cavity  into  which  the  pulmonary  veins  empty.  The  septum  be-, 
tween  the  auricles,  when  viewed  on  this  side,  has  the  place  of  the 
fossa  ovalis  marked  out  principally  by  its  diaphanous  condition. 
Occasionally,  there  is  some  appearance  of  the  valve  which  once 
existed  there. 

At  the  inferior  part  of  the  anterior  side  of  this  cavity  is  found  the. 
opening  between  it  and  the  left  ventricle,  also  called  Ostium  Veno-„ 
sum  ; it  is  circular,  and  rather  more  than  an  inch  in  diameter,  re-, 
sembling  strongly  the  corresponding  orifice  of  the  right  side  of  the. 
heart. 

The  Left  Ventricle  ( Ventriculus  Sinister,  Posterior)  in  the  shape. 

20* 


226 


CIRCULATORY  SYSTEM. 


of  its  cavity  resembles  a long  ovoidal  or  conical  body.  Its  parietes 
are  generally  three  times  as  thick  as  those  of  the  right  ventricle , 
amounting  to  about  eight  lines:  it  is  thicker,  however,  at  its  inferior 
than  at  its  superior  part,  as  it  gradually  decreases  in  approaching 
the  aorta.. 

Its  internal  surface  is  arranged  on  the  same  principle  with  that  of 
the  right  ventricle,  being  roughened  by  the  presence  of  numerous 
fleshy  columns  ( Columnce  Cameo)  some  of  which  are  connected 
with  the  valvular  apparatus  between  it  and  the  left  auricle : others 
form  an  intricate  reticular  texture  on  its  sides,  and  a few  pass  from 
one  side  to  the  other.  As  this  surface  approaches  the  orifice  of  the 
aorta,  it  becomes  smooth,  so  that  no  impediment  may  be  afforded 
to  the  passage  of  the  blood. 

The  Ostium  Venosum,  on  the  side  of  this  cavity,  has  its  margin 
looking  tendinous,  and  furnished' with  a duplicature  of  the  lining 
membrane  that  surrounds  it.  This  duplication,  by  being  severed 
on  its  loose  edge  into  two  divisions,  obtains  the  name  of  Mitral 
Valve,  ( Valvula  Mitralis.)  Its  margin  is  secured  from  being  pushed 
into  the  left  auricle  by  numerous  chordae  tendineae,  which  are  at- 
tached by  their  other  extremities  to  four  or  five  columnae  carneae  pro- 
jecting from  the  surface  of  the  ventricle.  The  whole  internal  ar- 
rangement of  this  cavity  indicates  a great  increase  of  strength  over 
that  of  the  right  side  : in  the  robustness  of  its  fleshy  columns;  the 
number  and  size  of  its  tendinous  chords  ;■  and  the  greater  thickness 
of  its  valve.  The  upper  division  of  the  mitral  valve  is  placed  im- 
mediately below  the  orifice  of  the  aorta,  and  is  considerably  broader 
than  the  other,  so  that  when  it  opens  to  admit  blood,  it  is  in  some 
measure  thrown  over  the  aortic  orifice.  There  is  less  of  an  inter- 
texture  among  the  tendinous  chords  here  than  on  the  right  side  of 
the  heart:  they  cluster  more,  and,  owing  to  the  breadth  of  the  ex- 
tremities of  the  fleshy  columns,  are  more  parallel. 

The  Septum  of  the  Ventricles  is  of  considerable  thickness,  being 
formed  almost  exclusively  by  the  continuation  of  the  fibres  of  the 
left  ventricle.  Where  the  large  columns  carnese  elevate  themselves 
on  its  surface,  its  thickness  is  increased.  Its  shape  is  somewhat 
triangular.  It  forms  a round  projection  into  the  right  vrentricle, 
while  its  other  surface,  which  presents  to  the  left,  is  concave  to  the 
same  degree.  It  is  rather  thinner  as  it  approaches  the  auricular 
septum  than  elsewhere.  Its  fibres  near  the  apex  are  less  closely 
connected  to  each  other. 


THE  HEART. 


227 


The  orifice  of  the  Aorta  is  furnished  with  three  Semi-lunar  Valves,* 
which,  in  the  mode  of  their  arrangement,  correspond  precisely  with 
those  of  the  pulmonary  artery.  They  are,  however,  thicker,  and 
the  Corpuscula  Aurantii  are  larger.  The  Sinuses  of  Valsalva,  at- 
tended with  a slight  dilatation  of  the  artery,  exist  in  the  same  way. 
Just  beyond  the  margin  of  the  right  and  of  the  left  valve,  are  ob- 
served the  orifices  of  the  two  coronary  arteries.  The  orifice  of  the 
aorta  is  somewhat  tendinous,  which  marks  out  the  distinction  of 
structure  between  it  and  the  ventricle. 

Of  the  Texture  of  the  Heart. 

The  Heart,  with  the  exception  of  the  serous  membrane  which 
lines  its  cavities,  called  the  Endocardium,  and  of  the  serous  lamina 
of  pericardium  which  covers  its  surface,  consists  almost  entirely  of 
muscular  fibres. 

The  sides  of  the  auricles,  as  stated,  are  much  thinner  than  those 
of  the  ventricles.  In  the  right  auricle,  the  stratum  of  muscular  fibres 
is  uniform  in  its  venous  portion,  but  on  the  sinus  is  arranged  into 
the  parallel  fasciculi  called  the  Musculi  Pectinati ; a circular  fasci- 
culus surrounds  the  orifice  of  the  descending  cava.  In  the  left 
auricle,  the  stratum  of  muscular  fibres  forms  a uniform  layer,  and  is 
also  thicker  than  on  the  right  side.  These  fasciculi  commence  on 
the  pulmonary  veins  and  run  transversely  across  the  auricle,  with 
the  exception  of  the  more  deeply  seated,  which  are  irregular,  and 
crossed  upon  each  other.  The  septum  of  the  auricles  is  also  formed 
by  a muscular  stratum. 

* Mr.  Erskine  Hazard  has  furnished  me  with  the  following  estimate  on  the 
action  of  these  valves  : — 

If  the  diameter  of  the  artery  be  put  = 10,  the 
length  of  the  superior  edge  of  the  valve  will  also  Tig'-  38. 

be  10.  The  arc  occupied  by  the  valve  will  be 
10.47  = 120°  of  the  circle.  The  valves,  w hen 
open,  will  either  assume  the  form  at  B,  or  that  of 
the  double  chord  of  60°,  as  at  A.  In  either  case,- 
being  .47  shorter  than  the  arc,  they  cannot  come 
in  contact  with  it,  and  must,  therefore,  leave  room 
for  the  blood  to  get  behind  them,  and  depress  the 
valves.  For  the  same  reason,  they  cannot  close 
the  orifice  of  the  coronary  arteries.  The  chord  of 
120°  would  be  8.67. 


228 


CIRCULATORY  SYSTEM. 


In  the  ventricles,  the  superficial  fasciculi  observe  a spiral  course, 
and  many  of  those  belonging  to  the  left  ventricle  may  be  traced 
over  the  right ; as  the  fibres  are  more  deeply  situated,  they  become 
shorter  and  more  interwoven.  In  the  septum,  between  the  ven- 
tricles, the  fibres  of  the  two  cavities  are  much  interlocked  ; but  with 
some  trouble  may  be  partially  separated.  The  fibres  of  the  colum- 
ns carnese  are  too  irregular  in  their  course,  to  admit  even  of  a gene- 
ral description.  It  would  appear,  however,  that  they  are  a conti- 
nuation of  the  superficial  spiral  fibres  of  the  ventricles  which  penetrate 
into  the  interior  of  the  heart  at  its  apex,  and  leave  there  a small 
foramen  which  is  closed  only  by  the  pericardium  externally,  and  the 
lining  membrane  of  the  heart.  M.  Gerdy  asserts,  that  all  the  fibres 
of  the  heart  arise  from,  and  are  inserted  into,  the  tendinous  rings 
forming  the  ostia  venosa  and  the  orifices  of  the  large  arteries ; having 
in  the  mean  time  traversed  the  course  which  is  peculiar  to  the  several 
fasciculi,  accordingto  their  being  superficial,  in  the  middle,  or  deep- 
seated.* 

All  the  cavities  of  the  heart  are  lined  by  a serous  membrane 
( Endocardium ) resembling  that  of  the  blood  vessels.  It  is  the  du- 
plicature  of  this  with  some  intermediate  fibrous  tissue,  which  in  each 
case  makes  the  valves,  the  thickness  of  wThich  is  proportionate  to  the 
requirements  of  the  circulation. 

Of  the  Blood  Vessels  of  the  Heart. 

The  Heart  is  furnished  with  both  arteries  and  veins,  which  belong 
to  its  nutritious  system. 

The  Arteries  called  Coronary,  arise,  as  observed,  from  the  trunk 
of  the  aorta,  somewhat  above  the  margins  of  the  semi-lunar  valves; 
so  that  when  the  latter  are  applied  against  the  aorta,  the  orifices  of 
these  arteries  are  still  visible. 

The  Right  Coronary  Artery  begins  above  the  anterior  valve,  and 
passes  to  the  right,  beneath  the  pulmonary  artery  ; it  then  shows 
itself  in  the  upper  part  of  the  fissure,  between  the  right  auricle  and 
right  ventricle,  and  follows  the  course  of  this  fissure  to  the  flat  side 
of  the  heart.  It  detaches,  as  it  goes  along,  several  small  branches, 

* For  a very  detailed  exposition  of  the  structure  of  the  Heart,  see  Wolff 
Act.  Acad.  Petrop.  1781 ; and  Gerdy,  Journal  Complementaire  du  Diet.  des. 
Sc.  Med.  vol.  x.  p.  97. 


VESSELS  OF  THE  HEART. 


229 


which  come  off  at  right  angles  from  it.  One  set  of  these  branches 
is  distributed  upon  the  right  ventricle,  and  another  set  upon  the 
right  auricle.  Small  branches  are  also  sent  from  it  to  the  root  of 
the  pulmonary  artery,  and  to  that  of  the  aorta. 

The  Left  Coronary  Artery  begins  above  the  left  semi-lunar  valve. 
While  its  root  is  still  obscured  by  the  pulmonary  artery,  it  divides 
into  two  principal  branches,  of  which  the  anterior  runs  in  the  fissure 
on  the  upper  part  of  the  septum  of  the  ventricles  to  the  apex  of  the 
heart,  and  in  this  course  distributes  branches  to  the  right  and  left 
ventricle  : those  to  the  right  anastomose  with  the  branches  of  the 
right  coronary  artery,  which  go  to  the  same  ventricle.  The  other 
branch  goes  along  the  groove,  on  the  septum,  between  the  left  au- 
ricle and  left  ventricle,  and  reaches  the  under  surface  of  the  heart; 
and  in  this  course  distributes  many  branches  to  the  left  auricle  and 
left  ventricle,  both  on  their  upper  and  under  surfaces.  It  anasto- 
moses freely  with  the  branches  of  the  trunk  that  run  along  the  upper 
part  of  the  septum. 

In  consequence  of  the  frequency  of  the  anastomoses  between  the 
two  coronary  arteries,  injecting  matter  thrown  into  one  very  readily 
finds  its  way  into  the  other. 

The  Coronary  Veins  receive  the  blood,  which  is  distributed  by 
the  coronary  arteries  through  the  substance  of  the  heart. 

The  Great  Coronary  Vein  ( Vena  Coronaria  Maxima  Cordis ) is 
formed  by  the  union  of  several  trunks,  which  run  from  the  apex 
towards  the  base  of  the  heart.  One  of  them  begins  at  the  apex, 
goes  along  the  superior  fissure  of  the  septum  of  the  ventricles,  and 
then  winds  to  the  left  side,  between  the  left  auricle,  and  the  left 
ventricle  : while  in  the  latter  position,  it  is  joined  by  several  trunks 
coming  from  the  left  ventricle  and  the  left  auricle : it,  finally,  emp- 
ties into  the  lower  part  of  the  right  auricle,  just  in  front,  as  men. 
tioned,  of  the  orifice  of  the  ascending  cava;  being  there  covered  by 
its  own  valve. 

The  Lesser  Coronary  Vein  (Vena  Cor  on.  Minor  Cordis)  lies  in 
the  inferior  fissure  of  the  septum  of  the  ventricles.  It  begins  at  the 
apex,  and,  going  backwards,  collects  the  blood  from  the  fiat  surface 


230 


CIRCULATORY  SYSTEM. 


of  the  heart,  principally  on  the  right  ventricle.  It  discharges  into 
the  great  coronary  vein,  just  before  the  latter  terminates  in  the  au- 
ricle. 

Besides  the  preceding  veins,  some  of  a smaller  size  exist  on  the 
right  ventricle  and  auricle,  and  about  the  root  of  the  aorta  and  pul- 
monary artery,  and  empty  by  several  orifices  into  the  right  auricle. 
There  are  also  some  veins  of  a still  smaller  size,  which  open  into 
all  the  cavities  of  the  heart  by  little  orifices,  called  the  Foramina  of 
Thebesius:  by  Mr.  Abernethy  they  are  considered  as  being  larger 
when  the  lungs  are  diseased.* 

The  Nerves  of  the  Heart  come  principally  from  the  cervical 
ganglions  of  the  sympathetic,  and  follow  the  course  of  the  coronary 
arteries.  It  has  been  doubted  whether  these  nerves  are  actually 
distributed  in  the  substance  of  the  heart,  from  the  presumption,  that 
as  they  cannot  be  traced  beyond  the  third  order  of  branches  of  the 
coronary  arteries,  they  are  limited  to  them.  But,  as  the  ramifica- 
tions of  the  sympathetic  are  bestowed  exclusively  upon  the  branches 
of  the  circulatory  system,  Meckel  has  very  properly  suggested,  that 
the  heart  being  also  supplied  with  nerves  from  the  same  source,  it 
follows  that  there  can  be  no  departure  from  the  general  rule,  as  the 
heart  is  nothing  more  than  the  fibrous  portion  of  the  blood  vessels 
more  completely  developed. 

While  the  circulation  continues,  as  both  auricles  contract  at  the 
same  instant,  whereby  the  blood  is  thrown  into  the  ventricles,  and 
as  immediately  afterwards  the  ventricles  contract  simultaneously 
also  ; whereby  the  blood  is  forced  into  the  aorta  and  the  pulmonary 
artery,  so  it  is  the  contraction  of  the  ventricles  which  causes  the 
heart  to  strike  against  the  parietes  of  the  thorax.  For,  as  was  first 
pointed  out  by  Dr.  W.  Hunter,  the  blood  which  is  forced  through 
the  large  arteries,  by  extending  them  diminishes  their  curvature,  or 
brings  them  more  into  a straight  line,  in  which  effort  the  heart 
bounds  up  from  the  tendinous  centre  of  the  diaphragm.  The  filling 
of  the  auricles,  while  this  is  going  on,  also  assists  in  protruding  the 
heart  forwards.  The  French  anatomists  assert,  that  during  the  con- 
traction of  the  ventricles,  their  extremity  is  elevated  or  bent  up- 
wards on  the  body  of  the  heart,  which  will  also  increase  the  mo- 
mentum of  the  stroke  against  the  thorax. 


* London  Philosophical  Transactions,  1798. 


BRANCHES  FROM  THE  ARCH  OF  THE  AORTA. 


231 


CHAPTER  II. 

Of  the  Arteries. 

SECT.  I. — THE  AORTA  AND  THE  BRANCHES  FROM  ITS 
CURVATURE. 

The  Aorta  is  the  trunk  of  the  arterial  system.  Having  arisen  from 
the  superior  posterior  end  of  the  left  ventricle,  its  root  passes  be- 
neath the  pulmonary  artery,  and  is  entirely  concealed  in  front  by  it. 
Keeping  to  the  right  it  emerges  at  the  base  of  the  heart,  between  the 
right  auricle  and  the  trunk  of  the  pulmonary  artery,  being  bounded  on 
the  right  side  by  the  descending  cava.  Continuing  its  ascent  it  forms 
a curvature  with  the  convexity  upwards,  and  the  summit  of  which 
rises  to  within  eight  or  twelve  lines  of  the  superior  edge  of  the 
sternum.  This  curvature  is  in  front  of  the  third  and  fourth  dorsal 
vertebrae,  and  its  direction  is  nearly  marked  out  by  a line  drawn 
from  the  anterior  extremity  of  the  third  right  rib,  to  the  posterior 
end  or  tubercle  of  the  third  one  on  the  left  side.  In  this  course, 
therefore,  the  aorta  passes  over  the  right  pulmonary  artery,  across 
the  left  bronchus,  and  applies  itself  to  the  left  side  of  the  spine,  about 
the  third  or  fourth  dorsal  vertebra.  It  is  this  curvature  which  ob- 
tains the  name  of  the  Arch  of  the  Aorta,  ( Arcus  Aortce.) 

Near  its  origin,  where  the  aorta  is  still  within  the  pericardium, 
it  has  very  commonly,  especially  in  persons  advanced  in  age,  a di- 
latation, which  is  called  the  Great  Sinus  to  distinguish  it  from  the 
lesser  sinuses,  or  those  of  Valsalva.  This  dilatation  is  useful  in 
diminishing  the  resistance  arising  from  the  curvature  of  the  aorta,  to 
the  current  of  blood ; or  rather  it  is  a provision  for  doing  away  with 
the  effects  of  friction,  as  by  it  a larger  current  of  blood  becomes  a 
compensation  for  diminished  velocity.  The  ascending  portion  of 
the  arch  is  to  the  right  of  the  vertebral  column,  the  descending  por- 
tion to  tire  left,  and  the  middle  or  horizontal  part  goes  in  front  of  the 
trachea  i 


232 


CIRCULATORY  SYSTEM. 


The  aorta,  in  its  descent  down  the  thorax,  is  placed  in  the  pos- 
terior mediastinum,  and  is  covered  on  one  of  its  sides,  by  the  left 
pleura,  while  the  other  side  is  in  contact  with  the  left  surface  of  the 
bodies  of  the  dorsal  vertebrae.  At  the  lower  part  of  the  thorax  it  in- 
clines towards  the  middle  line  of  the  vertebrae,  in  order  to  reach  the 
hiatus  aorticus  of  the  diaphragm,  through  which  it  penetrates  to  the 
abdomen.  In  the  abdomen  it  descends  in  front  of  the  lumbar  ver- 
tebrae, somewhat  on  their  left  side ; and  at  the  intervertebral  space 
between  the  fourth  and  fifth  vertebrae  of  the  loins,  or  somewhat  above, 
it  ceases,  by  being  divided  into  two  large  trunks,  the  Primitive 
Iliacs  ; one  for  each  lower  extremity,  and  the  corresponding  side  of 
the  pelvis. 

In  this  course  of  the  aorta,  from  the  heart  to  the  loins,  it  first  gives 
off  the  branches  which  supply  the  head  and  the  superior  extremities  ; 
then,  those  which  supply  the  sides  of  the  thorax : afterwards  in  the 
abdomen,  it  detaches  the  trunks  which  supply  the  viscera  and  the 
sides  of  the  latter  cavity. 

The  Coronary  Arteries  are,  strictly  speaking,  the  first  branches  of 
the  aorta,  but  as  they  belong  especially  to  the  heart,  their  descrip- 
tion is  associated  with  it.  In  all  the  space  between  them  and  the 
superior  convexity  of  the  aortic  arch  no  branches  are  given  off;  but 
as  the  aorta  is  crossing  the  trachea  three  considerable  trunks  arise 
from  it,  which  are  distributed  upon  the  head  and  the  upper  extremi- 
ties principally.  They  are,  the  Arteria  Innominata,  the  Left  Primi- 
tive Carotid,  and  the  Left  Subclavian. 

The  Arteria  Innominata  is  first  in  its  origin  : in  ascending  from 
left  to  right  in  front  of  the  trachea,  and  behind  the  Transverse  vein, 
it  crosses  the  trachea  very  obliquely  ; is  from  an  inch  to  an  inch  and  a 
half,  and  sometimes,  though  rarely,  two  inches  long,  when  it  divides 
into  the  right  subclavian  and  the  right  primitive  carotid.  The  left 
primitive  carotid  arises  from  the  aorta,  close  upon  the  left  border  of 
the  innominata ; frequently,  indeed,  from  a part  of  it.  The  left  sub- 
clavian artery,  at  its  origin  near  the  left  carotid,  generally  leaves  a 
distinct  interval  of  one,  two,  or  three  lines.  The  relative  situation 
of  these  trunks  is  particularly  alluded  to  in  the  account  of  the  supe- 
rior mediastinum.  The  last  two  are,  of  course,  longer  than  the 
corresponding  trunks  of  the  right  side,  by  the  whole  length  of  the 
arteria  innominata.  With  the  exceptions  connected  with  their  mode 


BRANCHES  FROM  THE  ARCH  OF  THE  AORTA. 


233 


of  origin,  the  arterial  trunks  of  the  two  sides  are  exactly  alike,  and 
have  the  same  mode  of  distribution. 

The  Common  Carotid  Artery  ( Carotis  Primitiva ) being  a branch 
of  the  innominata  on  the  right  side,  and  of  the  aorta  on  the  left,  goes 
up  the  neck  to  terminate  just  below  the  cornu  of  the  os  hyoides.  In 
the  early  part  of  its  course,  the  right  one  is  more  inclined  outwardly 
than  the  left,  owing  to  its  origin  from  the  arteria  innominata  in  front 
of,  and  to  the  right  side  of  the  trachea;  whereas,  the  left,  ascends 
almost  vertically. 

At  the  lower  part  of  the  neck,  just  above  the  sternum  and  the 
clavicle,  the  carotid  is  covered  by  the  sterno-hyoid  and  thyroid 
muscles,  and  by  the  sternal  portion  of  the  sterno-cleido-mastoid. 
It  is  crossed  obliquely  on  a line  with  the  lower  part  of  the  thyroid 
cartilage  of  the  larynx,  by  the  omo-hyoid  muscle.  It  lies  at  the  side 
of  the  thyroid  gland,  the  trachea,  the  larynx,  the  oesophagus,  and 
pharynx,  in  front  of  the  transverse  processes  of  the  cervical  vertebrae, 
and  the  longus  colli  muscle ; having  on  its  outer  margin,  but  some- 
what in  front,  the  internal  jugular  vein,  and  the  pneumogastric  nerve 
enclosed  in  the  same  sheath,  and  the  sympathetic  nerve  behind.  At 
the  side  of  the  larynx,  the  carotid  is  very  superficial,  and  with  the 
exception  of  being  crossed  by  the  omo-hyoideus  muscle,  it  is  only 
covered  by  the  platysma  myodes  and  the  integuments. 

The  Carotid  having  got  as  high  as  the  space  between  the  os 
hyoides  and  the  thyroid  cartilage,  but  varying  slightly  in  different 
subjects,  there  divides  into  two  large  trunks,  the  Internal  Carotid, 
which  goes  to  the  brain  and  to  the  eye  : and  the  External  Carotid, 
which  is  principally  distributed  upon  the  more  superficial  parts  of 
the  head  and  neck.  The  first  of  these  trunks  is  placed  behind  the 
other,  and  bends  outwardly  at  its  root : it  is  generally  the  largest  in 
infancy,  on  account  of  the  proportionate  volume  of  the  brain  at  that 
age  ; it  is  also  swollen  at  its  root,  so  as  to  form  a sinus  there,  re- 
sembling an  incipient  aneurism.  No  branch,  except  in  the  abnor - 
mons  cases,  is  given  off  from  the  common  carotid  between  its  origin 
and  bifurcation. 


Vol.  II.— 21 


234 


CIRCULATORY  SYSTEM. 


SECT.  II. — OF  THE  CAROTIDS,  AND  THEIR  BRANCHES.* 

The  Internal  Carotid,  ( Arteria  Carotis  Interna,)  in  the  adult,  is 
smaller  than  the  external,  and  extends  from  the  larynx  to  the  sella 
turcica.  It  ascends  between  the  external  corotid  and  the  vertebrae  of 
the  neck,  being  in  front  of  the  internal  jugular  vein,  and  having  the 
pneumogastric  nerve  at  its  outer  margin : as  it  gets  on  a level  with 
the  base  of  the  lower  jaw,  it  is  crossed  externally  by  the  digastric  and 
the  stylo-hyoid  muscles ; it  is  immediately  afterwards  concealed  in  the 
subsequent  part  of  its  ascent  by  the  ramus  of  the  lower  jaw.  Having 
gone  along  the  most  internal  or  deeply  seated  margin  of  the  parotid 
gland  and  of  the  styloid  process  of  the  temporal  bone,  at  the  side 
of  the  superior  constrictor  of  the  pharynx,  it  then  penetrates  into  the 
cranium  through  the  carotid  canal  of  the  temporal  bone. 

It  is  slightly  flexed  between  its  origin  and  the  carotid  canal : just 
before  it  reaches  the  latter,  it  curves  upwards  and  forwards.  The 
first  part  of  its  course  through  the  canal  is  vertical,  afterwards  it  goes 
horizontally  forwards  ; and  to  escape  from  the  canal  it  has  once  more 
to  ascend  almost  vertically,  which  brings  it  to  the  posterior  extre- 
mity of  the  Sella  Turcica.  On  the  side  of  the  Sella  Turcica  it  again 
passes  horizontally  forwards  through  the  cavernous  sinus ; and  at 
the  anterior  clinoid  process  it  once  more  ascends,  and,  having  pene- 
trated the  dura  mater,  it  reaches  the  brain. 

In  this  passage,  through  the  carotid  canal,  it  is  attended  by  the 
upper  extremity  of  the  sympathetic  nerve,  and  gives  one  or  more 
small  branches  to  the  petrous  bone  ; it  also  gives  a few  branches  to 
the  dura  mater  and  to  the  nerves  about  the  cavernous  sinus.  But, 
for  the  full  exposition  of  the  distribution  of  the  internal  carotid,  see 
the  arteries  of  the  Brain  and  of  the  Eye. 

The  External  Carotid  Artery  [Art.  Carotis  Externa ) extends  from 
the  termination  of  the  primitive  carotid,  to  the  neck  of  the  lower  jaw. 
In  the  early  part  of  its  course,  where  it  is  situated  in  front  of  the  in- 
ternal carotid,  and  between  the  pharynx  and  the  sterno-mastoid 
muscle,  it  is  comparatively  superficial,  being  only  enveloped  by  its 
sheath,  and  covered  by  the  platysma  myodes  and  the  skin.  Just 
above  this  place  it  is  crossed  externally  by  the  hypoglossal  nerve, 


* Anat.  Atlas,  Figs.  448  to  453  inclusive. 


CAROTIDS,  AND  THEIR  BRANCHES. 


235 


which  detaches  the  descending  branch  along  the  front  of  its  sheath 
and  of  that  of  the  primitive  carotid.  Somewhat  above  this  nerve, 
it  is  also  crossed  externally  by  the  digastric  and  the  stylo-hyoid 
muscle,  and  lies  there  on  the  side  of  the  superior  constrictor  muscle 
of  the  pharynx,  near  the  tonsil  gland.  About  its  middle,  it  is 
crossed  internally  by  the  stylo-glossus  and  the  stylo-pharyngeus 
muscle;  it  then  ascends  through  the  substance  of  the  parotid 
gland,  between  the  ramus  of  the  lower  jaw  and  the  ear,  to  its  ter- 
mination. 

Several  very  important  branches  are  given  off  from  the  external 
carotid  ; they  are  as  follow  : 

The  Superior  Thyroid  Artery  ( Art . Thyroidea  Superior)  arises 
from  the  external  carotid,  about  a line  above  its  root,  and  is  distri- 
buted to  the  larynx  and  to  the  thyroid  gland.  It  goes  at  first  inwards 
and  forwards  on  the  side  of  the  larynx,  being  covered  by  the  omo- 
liyoideus  muscle,  and  by  the  platysma  myodes ; it  then  descends 
under  the  sterno-thyroideus  to  the  upper  margin  of  the  lobe  of  the 
thyroid  gland.  In  this  course  it  performs  several  flexuosities,  of  con- 
siderable variety  in  different  individuals. 

The  Laryngeal  Branch  comes  from  it  near  the  superior  margin  of 
the  thyroid  cartilage ; this  branch  glides  in  between  the  thyro-hyoid 
muscle  and  the  middle  thyro-hyoid  membrane  or  ligament ; after  a 
short  course,  it  penetrates  the  latter,  and  is  then  distributed  in  a great 
number  of  small  twigs  to  the  muscles  and  to  the  lining  membrane 
of  the  larynx.  A small  trunk,  either  from  the  laryngeal  branch,  or 
from  the  thyroid  artery  itself,  is  spent  upon  the  crico-thyroid  muscle, 
and  traversing  the  front  surface  of  the  middle  crico-thyroid  ligament, 
anastomoses  with  its  fellow  : small  twigs  from  this  branch  penetrate 
to  the  interior  of  the  larynx  through  the  middle  crico-thyroid  liga- 
ment. Sometimes  this  crico-thyroid  ramus  is  superior  in  size  to  the 
one  above,  in  which  case  it  principally  supplies  the  interior  of  the 
larynx. 

The  Thyroid  Branch  is  the  continuation  of  the  principal  trunk : it 
penetrates  into  the  substance  of  the  thyroid  gland,  and  divides  into 
two  ramuscules,  one  of  which  goes  along  the  posterior  face  of  the 
lobe  of  the  gland,  and  anastomoses  with  the  inferior  thyroid ; the 
other  goes  along  the  upper  margin  of  the  gland,  and  anastomoses 
with  its  congener  of  the  opposite  side.  The  thyroidal  artery  is  split 
up  into  a great  many  branches  in  the  substance  of  the  gland,  it  also 


236 


CIRCULATORY  SYSTEM. 


sends  small  branches  to  the  pharynx,  oesophagus,  and  the  little  mus- 
cles on  the  front  of  the  neck. 

The  Lingual  Artery  [Art.  Lwgualis ) comes  from  the  external 
carotid  at  the  distance  of  from  six  to  twelve  lines  above  the  superior 
thyroid,  and  goes  to  the  tongue.  It  is  concealed  in  the  early  part 
of  its  course  by  the  digastric  and  the  stylo-hyoid  muscles  ; it  then 
penetrates  the  hyo-glossus  muscle  just  above  the  cornu  of  the  os 
hyoides,  or  goes  between  it  and  the  middle  constrictor  of  the  pharynx  ; 
it  then  ascends  between  the  hyo-glossus  and  the  genio-hyo-glossus 
muscle ; advancing  forwards,  it  is  placed  between  the  latter  and  the 
sublingual  gland,  and,  finally,  reaches  the  tip  of  the  tongue. 

The  lingual  artery  sends  off  the  following  branches.  At  the  root 
of  the  tongue  one  or  more  trunks  arise  from  it,  the  Dor  sales  Linguce 
which  go  to  the  base  of  this  organ,  the  tonsils,  the  palate,  and  the 
epiglottis;  one  of  these  branches  is  called  the  Inferior  palatine.  A 
little  farther  on,  the  lingual  detaches  another  branch,  the  Ramus  Sub- 
lingualis, which,  advancing  between  the  mylo-hyoid  and  the  genio- 
hyo-glossus  muscle,  and  above  the  sublingual  gland,  sends  a great 
many  ramifications  to  these  parts  and  to  the  lining  membrane  of  the 
mouth  ; it  is  sometimes  a branch  of  the  facial.  The  Ramus  Raninus, 
is  the  continuation  of  the  lingual;  it  advances  between  the  lingualis 
and  the  genio-hyo-glossus  muscle,  to  the  tip  of  the  tongue,  distri- 
buting continually  its  twigs  on  each  margin,  and  ends  there  by  anas- 
tomosing with  the  corresponding  artery  of  the  other  side. 

The  Facial  Artery  ( Arteria  Facialis , Maxillaris  Externa ) arises 
from  the  external  carotid  two  or  three  lines  above  the  lingual,  and 
is  spent  principally  on  the  side  of  the  face  below  the  eye.  It  is  of 
considerable  size,  and  very  tortuous;  its  root  is  concealed  by  the 
stylo-hyoid  and  the  digastric  muscle,  and  it  is  traversed  externally 
by  the  hypo-glossal  nerve.  It  goes  forward  v i Lin  theangle  of  the 
lower  jaw,  and  above  the  submaxillary  gland,  but  very  much  con- 
nected with  it : it  then  mounts  over  the  base  of  the  maxilla  inferior, 
at  the  anterior  margin  of  the  masseter  muscle,  and  afterwards  shapes 
its  course,  in  a serpentine  manner,  to  the  internal  canthus  of  the  eye, 
passing  between  the  muscles  and  the  integuments  of  the  face.  In 
this  course,  the  facial  artery  sends  off  the  folio  wing  branches: 

As  it  passes  by  the  submaxillary  gland  it  sends  several  twigs  to 
it : previously  it  also  sends  several  little  branches  to  the  contiguous 


CAROTIDS,  AND  THEIR  BRANCHES. 


237 


muscles,  as  the  internal  pterygoid,  digastric,  and  so  on  ; but  they 
are  too  small  to  be  of  much  consequence. 

The  Submental  branch  arises,  then,  on  a level  with  the  base  of  the 
lower  jaw;  it  advances  forwards  under  the  origin  of  the  mylo-hy- 
oideus,  and  above  the  anterior  belly  of  the  digastricus.  It  sends 
several  branches  to  these  muscles,  some  of  which  anastomose  with 
the  ranine  artery;  behind  the  symphysis  of  the  jaw  it  anastomoses 
with  its  fellow,  it  then  mounts  over  the  chin,  to  which  and  to  the 
lower  lip  it  is  distributed,  anastomosing  there  with  the  inferior  coro- 
nary artery  of  the  mouth,  and  with  the  inferior  maxillary  which 
comes  out  from  the  anterior  mental  foramen  in  the  lower  jaw. 

When  the  facial  artery  has  got  upon  the  face,  it  sends  backwards 
a small  branch  to  the  lower  part  of  the  masseter  muscle.  Somewhat 
above  this  it  sends  forwards  a branch  called  the  Inferior  Labial, 
which  is  distributed  upon  the  middle  of  the  chin.  When  it  gets  on 
a level  with  the  corner  of  the  mouth,  but  sometimes  lower  down,  it 
sends  forward,  under  the  depressor  anguli  oris,  the  Inferior  Coronary 
Artery,  to  the  lower  lip,  which  frequently  supplies  the  place  of  the 
inferior  labial  entirely ; but  when  the  latter  is  large,  the  coronary  is 
small  in  proportion  : a few  lines  higher  up  the  facial  sends  forward 
a third  branch,  the  Superior  Coronary,  which  goes  to  the  upper  lip. 
These  coronary  arteries  are  very  tortuous,  and  are  distributed  by 
many  branches  in  the  substance  of  the  lips : by  anastomosing  with 
their  congeners  of  the  other  side,  they  surround  the  mouth  com- 
pletely. The  superior  coronary  artery,  as  it  passes  under  the  nose,, 
sends  upwards  one  or  more  small  branches  to  the  integuments  of  its 
orifice  and  septum. 

After  this,  the  facial  artery,  in  ascending  towards  the  internal 
canthus  of  the  eye,  sends  a branch  to  the  ala  nasi,  and  another  to 
anastomose  with  the  infra-orbitar  artery.  It,  finally  terminates  at 
the  internal  canthus  of  the  eye  by  anastomosing  with  the  branches 
of  the  ophthalmic,  which  come  out  there  upon  the  side  of  the  root 
of  the  nose.  Several  ramuscules,  which  are  too  small  to  merit  spe- 
cial description,  are  given  by  the  facial  to  the  integuments  and  mus- 
cles of  the  face,  and  to  the  lower  eyelid. 

The  Inferior  Pharyngeal  Artery  [Art.  Pharyngea  Inferior , ascen- 
dens ) is  one  of  the  smallest  of  the  original  branches  of  the  external 
carotid,  and  generally  arises  opposite  to  the  lingual ; but  there  is. 
much  variety  in  the  latter  respect,  it  being  sometimes  higher  up  or. 

21* 


238 


CIRCULATORY  SYSTEM. 


lower  down,  and  not  unfrequently  a branch  of  one  of  the  other  arte- 
ries, instead  of  being  an  original  trunk.  It  ascends  on  the  side  of 
the  pharynx,  between  the  external  and  the  internal  carotid,  and  is 
covered  by  the  stylo-pharyngeus  muscle.  It  is  principally  distri- 
buted on  the  constrictor  muscles  of  the  pharynx,  and  upon  their 
lining  membrane.  But  one  of  its  branches,  called  the  Posterior 
Meningeal  Artery,  ascends  through  the  posterior  foramen  lacerum 
of  the  cranium,  between  the  jugular  vein  and  the  pneumo-gastric 
nerve,  and  is  distributed  on  the  contiguous  dura  mater. 

The  Occipital  Artery  (Arteria  Occipitalis ) is  a very  considerable 
trunk,  which  comes  from  the  external  carotid,  generally  opposite  to 
the  facial,  and  is  spent  upon  the  integuments,  on  the  back  part  of  the 
head. 

At  its  root,  it  is  deeply  situated  in  the  side  of  the  neck,  below  the 
parotid  gland,  and  has  the  internal  jugular  vein  and  the  par  vagum 
on  its  inside.  It  goes  obliquely  backwards,  in  ascending  along  the 
posterior  belly  of  the  digastricus  between  the  transverse  process  of 
the  atlas  and  the  mastoid  portion  of  the  temporal  bone,  and  is  be- 
neath the  several  muscles  which  are  inserted  into  the  latter,  as  the 
sterno-mastoid,  the  splenius,  and  the  trachelo-mastoid.  It  is  covered, 
for  some  distance,  by  the  insertion  of  the  splenius  capitis,  and  be- 
comes at  length  superficial  at  the  posterior  margin  of  this  muscle. 
The  occipital  artery  is  distributed  as  follows: 

Shortly  after  its  origin,  it  sends  branches  to  the  digastric  muscle 
behind,  to  the  upper  part  of  the  sterno-mastoid  and  to  the  lymphatic 
glands  of  the  upper  part  of  the  neck.  While  enclosed  by  the  mus- 
cles on  the  back  of  the  neck,  it  also  sends  branches  to  them,  and 
anastomoses  thereby  with  the  vertebral  artery ; occasionally,  one  of 
these  branches  is  of  considerable  magnitude,  and  has  been  found  de- 
scending very  low  on  the  back,  between  the  splenius  and  the  com- 
plexus  muscle.  It  also  sends  a small  branch  to  the  dura  mater,  through 
the  mastoid  foramen  generally,  but  sometimes  through  the  posterior 
foramen  lacerum.  When  the  stylo-mastoid  artery  is  wanting,  it  also 
detaches  a branch  through  the  stylo-mastoid  foramen  to  the  internal 
parts  of  the  ear. 

The  occipital  artery,  having  become  superficial  at  the  internal 
margin  of  the  splenius  on  the  occiput,  ascends  on  the  latter  bone 
towards  the  vertex  in  a tortuous  manner,  sending  off,  on  each  side, 


CAROTIDS,  AND  THEIR  BRANCHES. 


239 


many  small  ramifications.  It  ends  by  anastomosing  with  the  pos- 
terior temporal  artery. 

The  Posterior  Auricular  Artery  (Art.  Auricular  is  Posterior ) arises 
a little  above  the  last,  at  the  lower  edge  of  the  parotid  gland,  from 
the  external  carotid,  and  is  one  of  its  smallest  branches.  It  ascends 
backwards  enclosed  by  the  parotid  gland,  and  afterwards  between 
the  meatus  auditorius  externus  and  the  mastoid  bone:  at  the  latter 
place,  it  sends  a ramification  to  the  internal  side  of  the  external 
ear;  it  then  ascends  and  is  distributed,  by  small  branches,  on  the 
contiguous  integuments  of  the  side  of  the  head.  While  still  in- 
volved in  the  parotid  gland,  it  sends  some  small  ramifications 
through  the  meatus  externus  to  its  lining  membrane  and  the  mem- 
brana  tympani.  It  then  detaches  a branch  through  the  stylo-mastoid 
foramen,  from  which  the  whole  artery  is  also  named  Sty  lo-Mastoid ; 
but  this  branch,  as  stated,  sometimes  comes  from  the  occipital. 
The  stylo-mastoid  passes  along  the  aqueduct  of  Fallopius,  detaching 
its  arterioles  to  the  tympanum  and  to  the  labyrinth. 

The  External  Carotid  having  given  off  these  trunks,  penetrates 
vertically  through  the  inner  margin  of  the  parotid  gland,  and  gives 
to  it  several  small  twigs.  When  it  arrives  on  a line  with  the  neck 
of  the  lower  jaw,  it  divides  into  two  large  trunks;  one  of  them,  the 
Internal  Maxillary,  goes  to  the  parts  within  the  ramus  of  the  low'er 
jaw ; the  other,  being  smaller,  is  the  Temporal  Artery. 

The  Temporal  Artery  ( Arteria  Temporalis ) continues  to  ascend 
through  the  substance  of  the  parotid,  but  becomes  superficial  in 
front  of  the  meatus  externus,  in  mounting  over  the  root  of  the 
zygoma ; it  is  then  distributed  to  the  integuments  on  the  side  of  the 
head.  It  frequently  sends  off  one  or  two  ramifications,  of  but  little 
volume,  to  the  masseter  muscle.  Just  above  its  root,  and  while 
surrounded  by  the  parotid,  a branch  of  some  importance,  the  Trans- 
verse Facial,  ( Transversalis  Faciei ,)  leaves  it,  and  crosses,  horizon- 
tally, the  masseter  muscle,  just  belowr  the  parotid  duct,  sometimes 
above  it.  This  branch  is  distributed  to  the  adjacent  integuments 
and  muscles,  and  terminates  in  front  by  anastomosing  with  the  facial 
and  the  infra-orb itar  artery. 

A little  below  the  zygoma,  the  Middle  Temporal  artery  [Art. 
Temp.  Media)  comes  off  from  the  Temporal,  and  ascending  with  the 
parent  trunk,  perforates  the  temporal  fascia  at  the  upper  margin  of 


240 


CIRCULATORY  SYSTEM. 


the  zygoma,  and  is  distributed  to  the  temporal  muscle  by  many 
ramifications,  which  anastomose  with  the  deep-seated  temporal  arte- 
ries. After  this,  some  small  twigs,  called  Auricular,  go  to  the  ex- 
ternal ear  from  the  trunk  of  the  temporal  artery. 

The  temporal  artery,  having  ascended  for  an  inch  or  so  between 
the  aponeurosis  of  the  temporal  muscle  and  the  skin,  it  divides  into 
an  Anterior  and  a Posterior  Branch.  The  former  ascends  towards 
the  side  of  the  os  frontis,  and  is  distributed  in  ramuscules  to  the  orbi- 
cularis palpebrarum,  the  anterior  belly  of  the  occipito  frontalis,  and 
the  integuments  of  the  front  of  the  cranium,  anastomosing  with  the 
frontal  artery  and  the  temporal  of  the  other  side.  The  posterior 
branch  is  distributed  on  the  integuments  of  the  middle  of  the  side  of 
the  cranium,  anastomosing  with  the  anterior  branch,  with  its  fellow' 
of  the  other  side,  and  with  the  occipital  artery. 

The  Internal  Maxillary  Artery  ( Arteria  Maxillaris  Interna)  winds 
round  the  neck  of  the  lower  jaw,  and,  passing  between  the  ptery- 
goid muscles,  proceeds  in  a tortuous  manner  to  the  deepest  points 
of  the  zygomatic  fossa.  The  first  part  of  its  course  is  horizontally 
inwards  ; it  then  ascends  in  front  of  the  pterygoideus  externus  to 
the  bottom  of  the  temporal  bone,  or  the  spinous  process  of  the  sphe- 
noidal : it  then  passes  forwards,  within  the  temporal  muscle,  to  the 
upper  part  of  the  pterygo-maxillary  fossa. 

It  sends  off  several  branches,  and  commonly  in  the  following 
order : — 

1.  The  Arteria  Tympanica,  to  the  tympanum,  through  the  glenoid 
fissure. 

2.  The  Arteria  Meningea  Parva,  to  the  dura  mater,  through  the 
foramen  ovale.  It  is  most  frequently  a branch  of. the  next. 

3.  The  Arteria  Meningea  Magna,  or  Media,  to  the  dura  mater, 
through  the  foramen  spinale.  This  branch  having  entered  the  cra- 
nium, is  distributed  upon  the  dura  mater  in  the  manner  marked  off 
by  the  furrows  upon  the  internal  face  of  the  temporal,  the  parietal, 
and  the  frontal  bones.  One  of  its  branches  enters  the  aqueduct  of 
Fallopius,  through  the  Vidian  Foramen,  and  is  distributed  upon  the 
internal  parts  of  the  organ  of  hearing,  anastomosing  with  the  stylo- 
mastoid artery. 


CAROTIDS,  AND  THEIR  BRANCHES. 


241 


4.  The  Arteria  Maxillaris,  or  Dentalis  Inferior,  descends  along 
the  internal  face  of  the  ramus  of  the  lower  jaw,  and  having  sent  off 
some  ramifications  of  small  size  to  the  contiguous  muscles  and  the 
lining  membrane  of  the  mouth,  it  enters  the  posterior  mental  foramen 
with  the  inferior  dental  nerve.  Going  along  the  canal  in  the  sub- 
stance of  the  lower  jaw,  it  detaches  successively  from  its  superior 
margin  ramifications  to  the  teeth.  At  the  anterior  mental  foramen 
a trunk  is  sent  forward  as  far  as  the  symphysis,  which  supplies  in 
its  course  the  canine  and  incisor  teeth  ; the  remainder  of  the  inferior 
maxillary  artery  comes  out  at  the  foramen,  and  supplies  the  chin, 
anastomosing  with  the  facial  artery. 

5.  The  Arteriae  Teraporales  Profundae  are  two  in  number.  The 
first  of  them,  called  Posterior,  arises  next  to  the  inferior  maxillary. 
It  is  concealed  between  the  external  pterygoid  and  the  temporal 
muscle  for  some  distance  ; it  then  ascends  in  the  posterior  part  of  the 
temporal  fossa,  beneath  the  temporal  muscle,  and  is  minutely  distri- 
buted upon  it.  The  Anterior  deep  temporal  artery  is  separated  from 
the  posterior,  in  its  origin  from  the  external  maxillary,  by  the  ptery- 
goid and  the  buccal  arteries.  It  arises  near  the  pterygo-maxillary 
fossa;  and,  ascending  between  the  temporal  muscle  and  the  fore 
part  of  the  corresponding  fossa,  it  is  minutely  distributed  upon  the 
former, -anastomosing  with  the  posterior  deep,  and  with  the  middle 
temporal  artery. 

6.  The  Arteriae  Pterygoideas  arise  after  the  posterior  deep  tem- 
poral. They  vary  considerably  in  regard  to  number,  size,  and  origin, 
and  are  distributed  upon  the  pterygoid  muscles,  as  their  name  implies. 
One  of  their  branches,  which  is  sometimes  an  independent  trunk  from 
the  internal  maxillary,  goes  between  the  posterior  margin  of  the  tem- 
poral muscle  and  of  the  neck  of  the  lower  jaw,  in  front  of  the  latter, 
to  be  distributed  upon  the  internal  face  of  the  masseter  muscle. 

7.  The  Arteria  Buccalis,  sometimes  a branch  of  the  internal 
maxillary,  but  frequently  coming  from  one  of  its  trunks,  either  the 
alveolar  or  the  anterior  temporal,  passes  along  the  external  face  of 
the  upper  jaw,  and  distributes  its  branches  to  the  buccinator  and 
zygomatic  muscles,  and  to  the  lining  membrane  of  the  mouth. 

8.  The  Arteria  Maxillaris  Superior,  or  Alveolaris,  proceeds  down- 


242 


CIRCULATORY  SYSTEM. 


wards  and  forwards  in  winding  round  the  tuber  of  the  upper  jaw 
bone.  It  first  sends  some  ramifications  through  the  bone  to  the  roots 
of  the  great  and  small  molar  teeth,  and  to  the  lining  membrane  of 
the  maxillary  sinus ; it  then  passes  forwards  along  the  gums,  near 
the  buccinator,  and  gives  ramifications  to  them  and  to  the  contiguous 
muscles. 

9.  The  Arteria  Infra-orbitalis  comes  from  the  internal  maxillary, 
at  the  upper  part  of  the  pterygo-maxillary  fossa ; it  sends  some  in- 
considerable ramifications  to  the  fat  and  the  periosteum  of  the  orbit, 
through  the  spheno-maxillary  fissure.  It  then  enters  the  infra-orbi- 
tary  canal,  and  passes  through  it  with  the  infra-orbitary  nerve.  On 
arriving  near  the  anterior  orifice  of  the  canal,  it  detaches  downwards 
a branch  which  goes  to  the  canine  and  the  incisor  teeth,  and  to  the 
lining  membrane  of  the  antrum.  It  then  gets  to  the  face  below  the 
origin  of  the  levator  labii  superioris  muscle,  and  is  distributed  upon 
the  muscles  in  front  of  the  upper  maxilla,  anastomosing  with  the 
facial  and  with  the  ophthalmic  artery. 

10.  The  Arteria  Palatina  Superior  descends  through  the  posterior 
palatine  canal,  and  having  reached  the  mouth,  leaves  some  ramifica- 
tions with  the  soft  palate : it  then  advances-  between  the  bones  and 
the  lining  membrane  of  the  roof  of  the  mouth,  and  disperses  itself  in 
several  small  twigs;  one  of  which  passes  through  the  foramen  in- 
cisivum  into  the  nostril. 

11.  The  Arteria  Pharyngea  Superior  is  sometimes  a branch  of  the 
last,  and  is  spent  upon  that  portion  of  the  pharynx  bordering  on  the 
pterygoid  processes. 

12.  The  Arteria  Spheno-Palatina  is  the  terminating  trunk  of  the 
internal  maxillary : it  enters  the  nose  through  the  spheno-palatine 
foramen,  and  divides  into  two  branches,  which  are  minutely  dis- 
tributed over  the  Schneiderian  membrane.  One  of  them  descends 
along  the  septum  narium  ; the  other  along  the  external  margin  of  the 
posterior  naris,  and  divides  into  two  principal  ramuscules,  one  of 
which  is  dispersed  along  the  middle  turbinated,  and  the  other  along 
the  inferior  turbinated  bone. 


SUBCLAVIAN,  AND  ITS  BRANCHES, 


243 


SECT.  m. — OF  THE  SUBCLAVIAN  ARTERY,  AND  ITS 
BRANCHES.* 

The  Subclavian  Artery  ( Arteria  Subclavia)  of  the  right  side 
having  arisen  from  the  innominata,  and  that  of  the  left  from  the 
aorta,  they  each  go  over  the  first  rib  of  their  respective  sides,  ad- 
hering closely  to  it,  in  the  bottom  of  the  interval  between  the  sca- 
lenus anticus  and  medius  muscle.  The  right  subclavian  is  much 
shorter,  and  more  superficial  than  the  left,  from  its  origin  to  the 
scaleni  muscles.  Near  the  latter  they  are  each  covered  in  front  by 
the  sternal  end  of  the  clavicle,  by  the  sterno-hyoid  and  thyroid 
muscle,  and  by  the  subclavian  vein  of  the  corresponding  side ; be- 
hind they  are  separated  from  the  vertebral  column  by  the  longus 
colli  muscle  ; below  them  is  the  pleura,  the  left  artery  being  in  con- 
tact with  it  for  its  whole  passage  in  the  thorax;  and  on  their  internal 
side  is  the  primitive  carotid.  The  subclavian  of  the  right  side 
is  crossed  near  the  scalenus  anticus  by  the  par  vagum ; the 
phrenic  nerve  also  goes  in  front  of  it,  but  on  the  internal  edge  of 
the  scalenus.  The  subclavian  of  the  left  side  having  a course  almost 
vertical  from  its  origin  to  the  interval  of  the  scaleni  muscles,  is  nearly 
parallel  with  and  behind  the  primitive  carotid  of  that  side  ; the 
phrenic  nerve  has  the  same  relative  position  with  it  as  on  the  right 
side ; but  the  par  vagum  goes  parallel  with,  and  in  front  of  the  sub- 
Flavian  artery,  for  some  distance  along  the  root  of  the  latter. 

At  the  inner  margin  of  the  Scaleni  Muscles  the  Subclavian  gives 
off  a cluster  of  trunks  ; to  wit,  the  Vertebral ; the  Inferior  Thyroid; 
the  Superior  Intercostal ; the  Internal  Mammary  ; and  the  Posterior 
Cervical  Artery.  They  sometimes  arise  distinctly,  and  after  the 
order  mentioned : but  there  is  too  great  a diversity  in  subjects  to 
establish  any  rule  on  these  points. 

1.  The  Vertebral  Artery  ( Arteria  Vertebralis ) is  the  most  volu- 
minous of  the  branches  of  the  Subclavian.  Immediately  after  its 
origin  it  ascends  on  the  side  of  the  spine,  and  enters  the  canal  of  the 
transverse  processes  of  the  neck  at  the  sixth  vertebra.  Pursuing 
this  course,  it  gets  into  the  cavity  of  the  cranium  through  the  fora- 
men magnum  occipitis,  and  is  distributed  to  the  brain  in  the  manner 
mentioned  in  the  description  of  that  organ. 

* Anat.  Atlas,  Figs.  454  to  460  inclusive. 


244 


CIRCULATORY  SYSTEM. 


While  in  the  canal  of  the  transverse  processes,  it  sends  off 
several  branches  to  the  heads  of  the  contiguous  muscles,  and  to  the 
medulla  spinalis  of  the  neck.  The  vertebral  artery,  like  some 
others,  is  spindle-shaped,  its  size  augmenting  as  it  recedes  from 
its  origin ; this  imparts  some  advantage  to  the  current  of  the 
blood. 

2.  The  Inferior  Thyroid  Artery  ( Arteria  Thyroidea  Inferior)  arises 
from  the  upper  face  of  the  subclavian,  and  goes  to  the  thyroid  gland. 
It  ascends  at  first  on  the  internal  margin  of  the  scalenus  medius 
muscle,  and  then  turns  suddenly  inwards  between  the  vertebrae  and 
the  great  vessels  of  the  neck. 

In  this  course  several  unimportant  twigs  are  sent  from  it  to  the 
contiguous  parts.  Near  its  root  it  detaches  the  Anterior,  or  the 
Ascending  Cervical  Artery,  which  going  up  the  neck  is  spent  upon 
the  heads  of  the  muscles  arising  from  the  transverse  processes,  as 
the  scaleni,  the  longus  colli,  and  so  on.  The  inferior  thyroidal 
then  gets  to  the  thyroid  gland,  and  is  very  minutely  distributed  to 
it,  anastomosing  with  the  . other  arteries  which  supply  the  same 
organ. 

3.  The  Superior  Intercostal  Artery,  ( Arteria  Intercostalis  Superior,) 
arising  from  the  under  surface  of  the  subclavian  opposite  the  inferior 
thyroid,  descends  across  the  neck  of  the  first  rib,  and  divides  into 
two  branches,  which  supply  the  two  upper  intercostal  spaces  : each 
of  them  also  sends  backwards  near  the  vertebra  a small  trunk  to  the 
muscles  of  the  back. 

4.  The  Internal  Mammary  Artery  ( Arteria  Mammaria  Interna, 
Thoracica)  descends  at  first  along  the  internal  margin  of  the  scalenus 
anticus;  having  then  got  fairly  into  the  cavity  of  the  thorax,  it  con- 
tinues to  descend  across  the  posterior  face  of  the  costal  cartilages, 
parallel  with,  and  about  nine  lines  from  the  outer  edge  of  the  sternum, 
between  the  triangularis  slerni  and  the  intercostal  muscles. 

In  this  course,  besides  some  distinct  twigs  to  the  anterior  medi- 
astinum, it  sends  a branch  ( Phrenica  Superior)  which  accompanying 
the  phrenic  nerve  between  the  pleura  and  the  pericardium,  reaches 
finally  the  diaphragm,  and  is  spent  upon  it.  At  each  intercostal 
space  which  it  crosses,  the  internal  mammary  sends  outwards  a 
branch,  which  is  spent  upon  the  fore  part  of  the  intercostal  muscles, 


SUBCLAVIAN,  AND  ITS  BRANCHES. 


245 


and  anastomoses  with  the  corresponding  intercostal  artery:  other 
branches  also  leave  it  at  each  space,  which  getting  forwards  near 
the  sternum,  are  distributed  upon  the  pectoralis  major,  and  upon 
the  contiguous  muscles.  The  last  of  these  branches,  according  to 
M.  H.  Cloquet,  goes  transversely  across  the  ensiform  cartilage,  and, 
having  anastomosed  with  its  fellow,  descends  between  the  peritoneum 
and  the  linea  alba  to  the  suspensory  ligament  of  the  liver. 

On  a level  generally  with  the  anterior  extremity  of  the  sixth  rib, 
the  internal  mammary  divides  into  two  principal  branches;  the  most 
exterior  of  which,  descending  along  the  cartilaginous  margin  of  the 
thorax,  is  distributed  in  small  twigs  to  the  origin  there  of  the  dia- 
phragm and  of  the  transverse  muscle  of  the  abdomen.  The  internal 
branch  reaches  the  posterior  face  of  the  rectus  abdominis  muscle, 
and  is  dispersed  upon  it:  some  of  its  branches  go  as  low  as  the 
umbilicus,  to  anastomose  there  with  the  epigastric  artery. 

5.  The  Posterior  Cervical  Artery  ( Arteria  Cervicalis  Posterior , 
Transversa)  is  of  a very  unsettled  origin,  but  comes  most  frequently, 
either  from  the  subclavian  itself,  or  from  the  inferior  thyroid.  It  is 
but  small  in  some  subjects,  owing  to  its  place  being  supplied  by 
branches  from  the  adjoining  arteries. 

It  crosses  horizontally  the  root  of  the  neck  on  the  outer  face  of 
the  scaleni  muscles  above  the  subclavian  artery.  It  gets  under  the 
anterior  margin  of  the  trapezius,  and  is  there  divided  into  two  prin- 
cipal branches;  the  ascending  one  is  spent  upon  the  trapezius  and 
the  levator  scapulae;  the  other  descends  along  the  base  of  the 
scapula,  and  is  spent  in  ramifications  upon  the  rhomboidei  and  the 
serratus  major  muscle.  Several  branches  of  minor  size  and  import- 
ance are  sent  otf  from  the  posterior  cervical  artery  to  the  muscles 
on  the  back  of  the  neck  and  thorax. 

The  Subclavian  Artery  having  sent  off  the  preceding  branches, 
then  escapes  from  the  thorax  between  the  scaleni  muscles,  and  gets 
to  the  arm-pit  between  the  first  rib  and  the  subclavius  muscle.  The 
trunk  of  it  is  then  continued  downwards  through  the  axilla,  and  at 
the  inner  side  of  the  arm  to  the  elbow  joint. 

From  the  scaleni  muscles  to  the  elbow  its  relative  position  is  as 
follows:  When  it  first  appears  between  the  scaleni,  it  is  bounded 
above  and  behind  by  the  collected  fasciculi  of  the  axillary  plexus 
of  nerves.  In  front  it  is  separated  from  the  subclavian  vein  by  the 
Vol.  II. — 22 


246 


CIRCULATORY  SYSTEM. 


insertion  of  the  scalenus  anticus.  It  is  placed  at  the  bottom  of  the 
depression  between  the  sterno-mastoideus  and  the  trapezius,  being 
covered  by  the  skin,  the  platysma  myodes,  and  some  loose  cellular 
substance  below  the  latter.  It  then  descends  between  the  first  rib 
and  the  subclavius  muscle;  escaping  from  below  the  latter,  it  is 
covered  in  front  by  the  outer  margin  of  the  pectoralis  major  until  it 
reaches  the  lower  part  of  the  axilla;  and  in  this  course  it  has  the 
following  relation  to  other  parts:  it  passes  first  under  the  insertion 
of  the  pectoralis  minor,  then  under  the  shoulder  joint,  then  along 
the  internal  face  of  the  coraco-brachialis  muscle;  it  has  the  axillary 
vein  in  front  of  it,  and  the  axillary  nerves  plaited  around  it  as  far 
down  as  the  coracoid  process,  when  they  begin  to  disperse.  This 
artery  in  emerging  from  the  axilla  is  placed  upon  the  anterior  face 
of  the  insertion  of  the  latissimus  dorsi:  it  then  runs  out  the  length 
of  the  coraco-brachialis,  and  is  afterwards  conducted  along  the  inner 
margin  of  the  biceps  flexor  cubiti  and  of  its  tendinous  termination  ; 
it  lies  upon  the  anterior  face  of  the  brachialis  internus ; and  goes 
beneath  the  aponeurosis  coming  from  the  tendon  of  the  biceps  at 
the  bend  of  the  arm.  In  the  arm  it  is  concealed  only  by  the  integu- 
ments and  fascia,  and  is  bordered  internally  by  the  brachial  vein 
and  the  median  nerve. 

This  great  trunk  of  the  upper  extremity  loses  the  name  of  sub- 
clavian, to  be  called  Axillary  Artery,  [Art.  Axillaris,)  from  the  sub- 
clavian muscle  to  the  lower  margin  of  the  arm-pit : and  from  the 
latter  place  to  the  elbow-joint,  it  is  named  Brachial  Artery,  (Art. 
Brachialis .)  It  sends  off  many  interesting  branches  to  the  thorax, 
to  the  shoulder,  and  to  the  arm ; and,  finally,  terminates  a little  be- 
low or  at  the  elbow  joint  by  bifurcating. 


Of  the  Branches  of  the  Axillary  Artery. 

1.  The  Superior  Scapular  Artery  (Art.  Dorsalis  Superior  Scapula) 
varies  considerably  in  its  origin.  Sometimes  it  is  a branch  of  the 
subclavian,  sometimes  of  the  inferior  thyroid,  and  it  frequently 
comes  from  the  upper  part  of  the  axillary  ; so  that  it  canno’t  be  re- 
ferred, with  strict  propriety,  to  any  determined  origin.  When  it 
comes  from  the  axillary,  it  is  very  tortuous,  and  has  to  ascend  to  its 
destination,  which  removes  it  entirely  from  any  interference  with  the 
course  of  the  subclavian  over  the  first  rib,  and  over  the  upper  head 


AXILLARY,  AND  ITS  BRANCHES. 


247 


of  the  serratus  major  muscle.  But  in  the  other  cases,  it  goes  trans- 
versely backwards  and  outwards,  somewhat  below  the  posterior  cer- 
vical, and  along  the  posterior  inferior  margin  of  the  clavicle,  being 
covered  by  the  sterno-mastoideus,  the  platysma  myodes,  and  the 
trapezius;  consequently,  it  is  just  in  the  way  of  the  incisions  which 
are  made  for  reaching  the  subclavian  artery,  from  above  the  clavicle. 

It  reaches  the  superior  costa  of  the  scapula  near  the  root  of  the 
coracoid  process,  and  passing  through  the  notch  there,  is  distributed, 
by  one  large  branch,  upon  the  supra  spinatus  muscle ; and  by  another, 
which  goes  across  the  anterior  margin  of  the  spine  of  the  scapula,  to 
the  infra-spinatus  muscle.  In  its  course,  it  sends  off  several  small 
ramifications  to  contiguous  parts. 

2.  The  External  Mammary  Arteries  (Art.  Mammarice  seu  Tho- 
racica Externa)  arise  from  the  axillary,  between  the  subclavius  and 
the  pectoralis  minor  muscle.  There  are  four  principal  trunks,  which 
go  uniformly  to  certain  parts,  but  vary  considerably  in  their  origin  ; 
for  sometimes  the  latter  is  distinct  in  the  case  of  each  artery,  but 
frequently  otherwise.  Their  distribution  is  as  follows: 

a.  The  Thoracica  Superior  is  distributed  to  the  upper  part  of  the 
pectoralis  major  muscle,  and  to  the  pectoralis  minor.  Some  of  its 
branches  reach  the  mamma  in  the  female,  and  anastomose  with  the 
internal  mammary  and  with  the  intercostals. 

b.  The  Thoracica  Longa  descends  along  the  posterior  face  of  the 
pectoralis  major,  between  it  and  the  serratus  magnus.  It  gives  many 
branches  to  the  lower  part  of  the  pectoralis  major,  to  the  integuments, 
and,  in  the  female,  to  the  mamma ; anastomosing  likewise  with  the 
internal  mammary  and  with  the  intercostals. 

c.  The  Thoracica  Acromialis,  immediately  after  its  origin,  makes 
for  the  fissure  between  the  deltoid  and  the  great  pectoral  muscle, 
and  divides  there  into  an  ascending  and  a descending  branch.  The 
former  reaches  the  clavicle,  and  is  partly  distributed  superficially 
along  it,  partly  to  the  contiguous  muscles,  and  to  the  shoulder  arti- 
culation. The  other  branch  follows  the  cephalic  vein  along  the  in- 
terstice between  the  deltoides  and  pectoralis  major,  and  is,  finally, 
distributed  to  these  muscles  and  to  the  integuments. 

d.  The  Thoracica  Axillaris  is  irregular,  both  in  regard  to  the 
number  of  its  branches  and  to  their  origin.  Instead  of  a distinct 
origin  by  one  or  more  trunks  from  the  axillary  artery,  the  branches 
belonging  to  the  name  of  thoracica  axillaris,  are  sometimes  derived 


248 


CIRCULATORY  SYSTEM. 


from  the  other  thoracic  arteries.  They  are  generally  distributed  only 
to  the  fat  and  the  lymphatic  glands  in  the  axilla.  They  occasionally 
exist  primitively  as  a large  trunk,  which  runs  on  the  scapular  face  of 
the  serratus  major  the  whole  length  of  the  scapula,  and  is  distributed 
to  the  adjacent  muscles,  and  to  the  fat  and  glands  of  the  axilla. 

3.  The  Scapular  Artery  ( Arteria  Scapulans  communis , Subscapu- 
laris ) arises  from  the  axillary  below  the  shoulder  joint,  at  or  near  the 
anterior  margin  of  the  subscapularis  muscle.  Giving  off  some  in- 
considerable branches  to  the  lymphatic  glands  of  the  arm-pit,  it 
descends  along  the  anterior  margin  of  the  subscapularis,  and  is  dis- 
tributed to  it,  to  the  latissimus  dorsi,  and  to  the  teres  major  and 
minor  muscles, 

A little  below  the  neck  of  the  scapula,  it  detaches  a large  trunk, 
the  Dorsalis  Inferior  Scapulm,  which  winding  around  the  inferior 
costa  of  the  bone  over  the  anterior  margin  of  the  subscapularis  and 
the  teres  minor,  reaches  the  fossa  infra-spinata.  This  trunk  then 
divides  into  two  branches  : one  of  which  is  distributed  superficially 
between  the  scapular  aponeurosis  and  the  infra-spinatus,  and  the 
other  more  deeply  near  the  dorsum  of  the  bone : one  of  the  ramus- 
cles  of  the  latter  ascends  beneath  the  neck  of  the  acromion  to  anas- 
tomose with  the  Dorsalis  Superior  Scapulae. 

4.  The  Anterior  Circumflex  Artery  {Art.  Circumfiexa  Anterior, 
Articularis  Anterior)  is  about  the  size  of  a crow  quill,  and  arises 
from  the  axillary  just  above  the  tendon  of  the  teres  major  and  of  the 
latissimus  dorsi.  It  adheres  closely  to,  and  surrounds  the  front  of 
the  neck  of  the  os  humeri,  passing  between  it,  the  coraco-brachialis, 
and  the  short  head  of  the  biceps.  It  then  divides  into  several 
branches,  some  of  which  go  to  the  deltoides,  and  anastomose  there 
with  the  posterior  circumflex ; others  go  immediately  to  the  articula- 
tion, and  either  terminate  on  it  or  ascend  to  the  muscles  on  the 
dorsum  of  the  scapula,  where  they  anastomose  with  the  scapular 
arteries. 

5.  The  Posterior  Circumflex  Artery  {Art.  Circumfiexa  Posterior) 
is  much  larger  than  the  last,  and  arises  from  the  axillary  somewhat 
below  it.  It  surrounds  the  posterior  face  of  the  neck  of  the  os 
humeri,  passing  between  it  and  the  long  head  of  the  triceps  muscle, 
below  the  insertion  of  the  teres  minor.  Many  of  its  ramifications 
go  to  the  capsular  ligament  of  the  articulation  and  to  the  muscles 


BRACHIAL,  AND  ITS  BRANCHES. 


249 


adhering  to  it.  But  this  artery  is  principally  intended  for  the  deltoid 
muscle,  to  the  internal  face  of  which  the  most  of  its  branches  go. 
It  anastomoses  with  the  anterior  circumflex,  and  with  the  scapular 
arteries. 

In  some  cases,  the  posterior  eircumflex  arises  from  the  axillary, 
below  instead  of  above,  the  tendinous  insertion  of  the  latissimus 
dorsi : when  this  happens,  it  commonly  gives  off  the  arteria  profunda 
major  of  the  arm,  and  afterwards  ascends  on  the  posterior  face  of  the 
tendon  to  its  appropriate  destination. 

Of  the  Branches  of  the  Brachial  Artery. 

1.  The  Profound  Artery  (Arteria  Profunda  Major  Humeri , Spi- 
ralis,) arises  from  the  brachial,  a little  below  the  tendinous  insertion 
of  the  latissimus  dorsi,  and  having  passed  downwards,  for  a short 
distance,  it  enters  the  interstice  between  the  first  and  the  third  head 
of  the  triceps  muscle,  and  winds  spirally  downwards  around  the  os 
humeri  in  company  with  the  radial  nerve.  On  the  outer  side  of  the 
arm,  it  becomes  superficial  between  the  margins  of  the  triceps  and 
of  the  brachialis  interims,  and  then  directs  its  course  between  the 
latter  and  the  supinator  longus  to  the  external  condyle. 

In  this  course,  the  artery  sends  several  branches  to  the  triceps 
muscle,  to  which,  indeed,  it  is  principally  destined.  Near  the  ex- 
ternal condyle,  it  supplies  the  brachialis  internus  and  the  heads  of 
the  extensor  muscles  of  the  fore-arm,  and  anastomoses  with  the 
recurrent  branch  of  the  radial  artery. 

2.  The  Small  Profound  Artery  (Art.  Profunda  Minor)  comes 
from  the  brachial,  twro  or  three  inches  below3 * * * 7  the  profunda  major, 
but  frequently  it  is  only  a branch  of  the  latter,  and  is  generally  much 
smaller.  It  is  distributed  superficially  on  the  internal  face  of  the 
triceps  at  its  lower  part,  and  has  its  terminating  branches  reaching 
as  far  as  the  internal  condyle. 

3.  The  Nutritious  Artery  (Art.  jYutri.tia)  is  the  next  in  order 

from  the  brachial,  and  arises  from  it  near  the  medullary  foramen  of 

the  os  humeri,  through  which  it  penetrates,  and  is  distributed  to 

the  lining  membrane  of  the  bone.  It  is  not  larger  than  a knitting 

needle. 


250 


CIRCULATORY  SYSTEM. 


4.  The  Anastomotic  Artery  ( Jlrteria  Anastomotica ) arises  from 
the  brachial  below  the  last,  and  is  larger  than  it.  It  lies  upon  the 
lower  internal  part  of  the  brachialis  internus  muscle,  and  crosses  the 
ridge  leading  to  the  internal  condyle  in  order  to  reach  the  depression 
between  the  latter  and  the  olecranon,  where  it  anastomoses  with  the 
ulnar  recurrent  artery.. 

The  preceding  is  a common  arrangement  of  the  branches  pro- 
ceeding from  the  brachial  artery,  yet  deviations  from  it  are  continu- 
ally met  with,  in  a deficiency  or  in  a redundancy  of  these  collateral 
trunks,  and  in  their  mode  of  origin.  An  account  of  all  the  varieties 
which  are  observed  here  would  be  almost  endless,  as  every  subject 
has  some  peculiarity.  Several  small  arteries  are  also  sent  from  the 
brachial  to  the  coraco-brachialis,  the  biceps,  the  brachialis  internus, 
and  to  the  triceps  muscle.  They,  for  the  most  part,  are,  simply, 
muscular  branches,  which  are  too  small  and  irregular  to  deserve  spe- 
cifying. 

A division  of  the  brachial  artery  into  two  trunks,  the  Radial  and 
the  Ulnar,  will  be  found  in  a majority  of  subjects  in  front  of  the 
brachialis  internus  muscle  on  a line  with  the  elbow  joint:  sometimes 
it  occurs  nearer  the  root  of  the  coronoid  process.  It  is,  however, 
by  no  means  rare  to  see  this  bifurcation  much  above  the  elbow. 
Examples  of  it  have  been  witnessed  at  every  point  between  the  latter 
and  the  arm-pit ; in  such  cases,  the  course  of  the  radial  artery  down 
the  fore-arm  is  generally  much  more  superficial  than  usual,  as  it  is 
placed  immediately  below  the  skin. 


Of  the  Radial  Artery. 

The  Radial  Artery  ( Arteria  Radialis)  is  smaller  than  the  ulnar, 
and  extends  from  the  elbow  to  the  hand.  In  the  upper  half  of  the 
fore-arm  it  is  placed  at  the  bottom  of  the  fissure  between  the  supi- 
nator radii  longus  and  the  pronator  teres  muscle.  Having  crossed 
the  insertion  of  the  latter,  it  runs  in  front  of  the  radius  between  the 
tendon  of  the  supinator  and  of  the  flexor  carpi  radialis.  Below 
the  styloid  process  of  the  radius  it  runs  between  the  outer  end  of 
the  carpus  and  the  extensor  muscles  of  the  thumb  ; it  then  pene- 
trates to  the  palm  of  the  hand  between  the  root  of  the  metacarpal 


RADIAL  ARTERY. 


251 


bone  of  the  thumb  and  of  the  fore-finger  above  the  abductor  indicis 
muscle. 

The  following  branches  are  sent  from  the  Radial  Artery. 

1.  The  Recurrens  Radialis  arises  at  the  neck  of  the  radius.  It 
winds,  externally  around  the  joint  between  the  external  condyle 
and  the  muscles  coming  from  it,  and  anastomoses  with  the  spiralis 
of  the  humeral  artery,  being  distributed  in  many  collateral  branches, 
to  the  joint  and  to  the  contiguous  muscles. 

2.  Several  small  and  irregular  muscular  branches  arise  from  the 
radial  artery,  in  its  progress  to  the  wrist:  they  have  no  appropriate 
names. 

3.  The  Superficialis  Volae  arises  from  the  radial  about  the  infe- 
rior margin  of  the  pronator  quadratus  muscle.  It  passes  superfi- 
cially over  the  process  of  the  trapezium  to  the  muscles  of  the  ball 
of  the  thumb,  and  one  of  its  terminating  branches  joins  the  arcus 
sublimis.  Sometimes  the  superficialis  voire  is  the  principal  branch 
of  the  radial. 

4.  The  Dorsalis  Carpi  arises  from  the  radial  at  the  carpus,  runs 
across  the  back  of  the  latter  below  the  extensor  tendons,  and  de- 
taches the  posterior  interosseous  arteries  of  the  back  of  the  hand. 
They  anastomose  w'ith  branches  from  the  ulnar  and  interosseous  arte- 
ries of  the  fore-arm. 

5.  The  Magna  Pollicis,  a terminating  branch  of  the  radial,  comes 
from  it  in  the  palm  of  the  hand  just  at  the  root  of  the  metacarpal 
bone  of  the  thumb.  It  runs  beneath  the  abductor  indicis,  and  at 
the  head  of  the  metacarpal  bone  divides  into  two  branches  which 
go  respectively  along  the  sides  of  the  thumb  to  its  extremity,  where 
they  anastomose  and  terminate. 

6.  The  Radialis  Indicis,  arising  at  the  same  place  with  the  latter, 
runs  along  the  metacarpal  bone  of  the  fore  finger,  and  along  the 
radial  side  of  the  same  finger  to  its  extremity. 

7.  The  Palmaris  Profunda  is  the  third  terminating  branch  of  the 
radial  artery.  It  arises  near  the  same  place  with  the  last  two,  crosses 


252 


CIRCULATORY  SYSTEM. 


the  hand  between  the  metacarpal  bones  and  the  flexor  tendons ; thus 
forming  the  Arcus  Profundus,  from  which  branches  proceed  to  the 
interossei  muscles  ; and  which  ends  on  the  ulnar  side  of  the  palm  of 
the  hand  by  a connexion  with  the  Arcus  Superficialis. 


Of  the  Ulnar  Artery. 

The  Ulnar  Artery,  ( Arteria  Ulnaris ,)  one  of  the  forks  of  the 
brachial  at  the  elbow,  passes  more  in  a line  with  it  than  the  radial 
artery  does.  It  goes,  immediately  after  its  origin,  under  several 
of  the  muscles  of  the  internal  condyle,  to  wit:  the  pronator  teres, 
flexor  radialis,  flexor  sublimis,  and  palmaris  longus,  and  between 
the  flexor  sublimis,  and  profundus  digitorum,  being  deeply  seated  ; 
getting  from  beneath  the  flexor  sublimis,  it  afterwards  runs  parallel 
with  the  ulna,  or  nearly  so,  lying  on  the  flexor  profundus  between 
the  flexor  ulnaris  and  the  ulnar  margin  of  the  flexor  sublimis,  and 
concealed  two-thirds  of  the  way  down  the  fore  arm  by  the  over- 
lapping of  these  muscles.  At  the  thin  part  of  the  fore  arm,  com- 
monly called  the  wrist,  it  is  superficial,  and  may  be  felt  pulsating 
in  the  living  body  at  the  radial  margin  of  the  tendon  of  the  flexor 
ulnaris. 

The  ulnar  artery,  at  the  carpus,  takes  a very  different  course  from 
the  radial;  for  it  passes  over  the  anterior  annular  ligament  of  the 
carpus  just  at  the  radial  side  of  the  os  pisiforme,  to  which  it  is  held 
by  a small  ligamentous  noose  ; it  then  proceeds  to  the  palm  of  the 
hand.  Between  the  aponeurosis  palmaris  and  the  flexor  tendons  it 
forms  that  curve  from  the  ulnar  to  the  radial  side  of  the  hand  called 
the  Arcus  Sublimis.  This  curve  commonly  begins  a little  beyond 
the  anterior  margin  of  the  annular  ligament,  and  presenting  its  con- 
vexity forwards,  terminates  about  the  middle  of  the  ball  of  the  thumb 
at  its  inner  margin. 

The  branches  sent  from  the  ulnar  artery  are  as  follow  : 

1.  The  Recurrens  Ulnaris  arises  from  the  ulnar  about  the  lower 
part  of  the  tubercle  of  the  radius,  and,  winding  upwards,  is  distri- 
buted in  small  branches  to  the  muscles  of  the  internal  condyle.  One 
of  its  ramuscules  goes  between  the  internal  condyle  and  the  olecranon 
process  to  anastomose  with  the  arteria  anastomotica  of  the  humeral. 


ULNAR  ARTERY. 


253 


2.  The  Interossea  arises  from  the  ulnar,  just  below  the  other.  It 
is  a large  trunk,  and  proceeds  but  a little  distance  when  it  divides 
into  two  principal  branches,  called  anterior  and  posterior  interosseal 
arteries. 

a.  The  Interossea  Anterior  is  much  the  larger ; it  runs  in  contact 
with  the  interosseous  ligament  to  the  upper  margin  of  the  pronator 
quadratus,  giving  off  branches  to  the  deep-seated  muscles  of  the  fore 
arm  in  its  course.  Under  the  pronator  it  perforates  the  interosseous 
ligament,  and  distributes  branches  to  the  back  of  the  carpus  and  of 
the  hand,  which  anastomose  with  branches  of  the  radial  and  posterior 
interosseal. 

b.  The  Interossea  Posterior  is  sometimes  a separate  trunk,  arising 
from  the  ulnar  just  above  the  former.  In  either  case  it  soon  per- 
forates the  interosseous  ligament  to  get  to  the  back  of  the  fore  arm. 
Here  it  sends  backwards  a Recurrent  Branch  ( Recurrens  Interossea) 
to  the  back  of  the  elbow,  which  anastomoses  with  the  recurrens 
ulnaris  and  radialis.  It  then  proceeds  downwards,  being  deeply 
seated  and  distributed  to  the  different  muscles  on  the  back  of  the 
fore  arm.  Some  of  its  branches  reach  the  wrist,  and  anastomose 
with  the  carpal  arteries. 

3.  The  ulnar  artery,  in  its  descent  on  the  fore  arm,  sends  off  many 
small  and  irregular  muscular  branches,  called  by  Professor  Chaussier, 
Cubito-muscular : they  do  not  require  description. 

4.  The  Dorsalis  Manus  leaves  the  ulnar  at  the  lower  end  of  the 
fore  arm,  and  passes  under  the  tendon  of  the  flexor  ulnaris  to  the 
back  of  the  hand.  It  there  meets  ramuscules  of  the  radial  and  inter- 
osseous, and  conjointly  they  supply  with  very  small  branches  the 
back  of  the  wrist,  of  the  metacarpus,  and  of  the  fingers. 

5.  As  the  Arcus  Sublimis  is  about  beginning,  the  ulnar  artery 
sends  superficial  but  small  branches  to  the  integuments  of  the  palm ; 
and  a little  farther  on,  a considerable  branch,  which  dives  into  the 
bottom  of  the  palm,  through  the  muscles  of  the  little  finger,  and  joins 
the  ulnar  extremity  of  the  arcus  profundus : this  is  the  Cubitalis 
Manus  Profunda  of  Haller. 


6.  The  Arcus  Sublimis  then  sends  a branch  to  the  ulnar  side  of 


254 


CIRCULATORY  SYSTEM. 


the  little  finger.  Afterwards  in  succession  three  digital  branches  are 
sent  off,  which,  arriving  at  the  interstices  between  the  heads  of  the 
several  metacarpal  bones,  each  divides  into  two  branches  to  supply 
the  sides  of  the  fingers  which  are  opposite  to  each  other ; one  branch 
is  called  Digito-radial,  the  other  Digito-ulnar,  according  to  the  side 
of  the  finger  on  which  the  artery  may  be  placed.  In  this  way  the 
radial  side  of  the  little  finger,  both  sides  of  the  ring  finger,  both  sides 
of  the  middle  finger,  and  the  ulnar  side  of  the  fore  finger  are  sup- 
plied. 

The  digital  arteries,  before  they  divide,  receive  each  a small 
branch  from  the  arcus  profundus.  The  digito-radial,  and  the  digito- 
ulnar  arteries,  pass  along  the  sides  of  the  fingers  in  front  to  their  ex- 
tremities; at  the  joints  and  extremities,  many  anastomoses  between 
the  arteries  of  the  two  sides  of  the  same  finger  occur. 

The  arcus  sublimis  terminates  on  the  radial  side  of  the  palm  by 
a branch  which  joins  the  inner  branch  of  the  Arteria  Magna  Pollicis 
of  the  Radial. 

The  most  frequent  distribution  of  the  arteries  of  the  hand  is  what 
has  just  been  described : anatomists  are,  however,  not  all  agreed  on 
this  point.  It  would  probably  be  more  just  to  say,  that  this  occurs 
more  frequently  than  any  other  single  arrangement.  The  varieties, 
in  fact,  are  so  great,  that  before  a hand  is  opened,  it  is  not  possible 
to  know  in  what  manner  its  arteries  will  be  distributed.  Sometimes 
the  Radial  Artery  furnishes  one  half  of  the  arcus  sublimis,  and  the 
Ulnar  the  other  half.  On  other  occasions,  the  interosseous  artery, 
or  the  superficialis  volae,  is  continued  as  a large  trunk  over  the  liga- 
ment of  the  wrist,  to  join  the  arcus  sublimis,  and  to  complete  the 
digital  arteries. 

SECT.  IV. — BRANCHES  OF  THE  DESCENDING  THORACIC 

AORTA.* 

The  Aorta,  in  its  course  from  the  lower  part  of  its  curvature  to 
the  crura  of  the  Diaphragm,  gives  off  several  branches  to  the  viscera 
and  to  the  parietes  of  the  thorax. 

The  Bronchial  Arteries  ( Arterice  Bronchioles ) are  the  nutritious 
vessels  of  the  lungs.  There  is  commonly  one  for  each  lung,  but 


*Anat.  Atlas,  Fig-.  461. 


DESCENDING  AORTA. 


255 


sometimes  two  or  more.  The  right  arises  frequently  from  the  supe- 
rior aortic  intercostal  artery,  instead  of  from  the  aorta,  while  the  left 
comes  from  the  latter : occasionally  they  have  a common  root. 

On  either  side  they  follow  the  course  of  the  bronchus  into  the 
substance  of  the  lung ; and  are  distributed  along  with  it,  by  ramifi- 
cations which  become  successively  finer  and  finer,  and  anastomose 
with  the  pulmonary  artery;  after  the  manner  mentioned  in  the  de- 
scription of  the  lungs.  Before  they  enter  the  latter,  they  send  some 
small  ramifications  to  the  posterior  mediastinum,  to  the  pericardium, 
and  to  the  black  bronchial  glands. 

The  (Esophageal  Arteries  ( Arteries  (Esophageal)  are  generally  five 
or  six  small  twigs  which  come  successively  from  the  descending 
thoracic  aorta.  They  ramify  minutely  in  the  substance  of  the  oeso- 
phagus, communicating  freely  with  each  other  : the  lowest  of  them 
also  anastomose  around  the  cardia  with  the  superior  artery  of  the 
stomach. 

The  Posterior  Arteries  of  the  Mediastinum,  (Arterice  Mediasti- 
nales  Posteriores,)  are  numerous  and  small ; they  come  from  the 
anterior  face  of  the  aorta,  as  well  as  from  the  branches  last  men- 
tioned; and  are  spent  upon  the  posterior  mediastinum,  and  upon 
its  contents. 

The  Intercostal  Arteries  ( Arterice  Intercostales  Inferior  es,  A or  tic  ce) 
of  the  aorta  supply  the  ten  lower  intercostal  spaces  on  each  side,  as 
the  two  upper  ones  are  supplied  by  the  subclavian  artery.  There  is 
commonly  an  intercostal  artery  arising  distinctly  from  the  aorta  for 
each  space,  but  sometimes  two  of  them  arise  from  a common  trunk. 
Those  for  the  right  side  having  to  cross  the  spine  behind  the  oeso- 
phagus and  the  vena  azygos,  are,  of  course,  longer  than  such  as  be- 
long to  the  left.  The  upper  ones  on  either  side  have  to  ascend,  in 
order  to  reach  their  destination. 

Each  artery  joins  the  rib  near  its  tubercle,  and  goes  along  the 
groove  in  its  lower  margin,  between  the  external  and  the  internal 
intercostal  muscle,  for  two-thirds  of  the  length  of  the  rib.  It  then 
abandons  the  groove,  and  divides  into  several  branches,  which  go 
to  the  intercostal  muscles  and  contiguous  parts,  and  anastomose  in 
front  with  the  internal  mammary  artery. 

As  each  intercostal  artery  passes  the  head  of  the  rib,  it  sends  a 


256 


CIRCULATORY  SYSTEM. 


branch  backwards;  ( ramus  dorsalis ,)  between  the  transverse  pro- 
cesses of  the  adjoining  vertebrae,  which  penetrates  to  the  posterior 
face  of  the  trunk,  and  is  distributed  to  the  muscles  and  skin  on  the 
side  of  the  spine.  A ramification  from  this  branch  enters  the  inter- 
vertebral foramen,  and  is  spent  upon  the  medulla  spinalis  and  its 
membranes. 

Each  intercostal  artery  also  gives  off,  about  the  middle  of  the  rib, 
a branch,  ( ramus  costalis  inferior ,)  much  smaller  than  the  trunk. 
This  branch  advances  along  the  upper  margin  of  the  rib  below,  and 
gives  ramifications  to  its  periosteum  and  to  the  adjacent  intercostal 
muscles. 

The  last  intercostal  artery  is  remarkable  for  its  size.  Its  origin  is 
concealed  by  the  small  muscle  of  the  diaphragm,  to  which  it  gives 
some  ramifications : it  then  passes,  at  the  under  margin  of  the  last 
rib,  behind  the  upper  end  of  the  quadratus  lumborum  muscle,  where 
it  divides  into  three  branches;  one  of  which  goes  transversely  to  the 
broad  muscles  of  the  abdomen;  while  the  other  two  descend  be- 
tween the  oblique  and  transverse  muscles  towards  the  crest  of  the 
ilium,  where  they  anastomose  with  the  lumbar  arteries,  and  with  the 
circumflexa  ilii. 


SECT.  V. — OF  THE  BRANCHES  OF  THE  ABDOMINAL  AORTA.* 

The  Phrenic  Arteries  ( Arterice  Pkrenicce ) are  two  in  number,  one 
for  the  right  and  the  other  for  the  left  side  of  the  diaphragm.  They 
arise  singly,  but  sometimes  by  a common  trunk,  from  the  front  of 
the  aorta,  immediately  on  the  latter  showing  itself  in  the  abdomen, 
between  the  crura  of  the  diaphragm ; consequently,  just  below  the 
crossing  of  the  muscular  fibres,  which  takes  place  between  the 
foramen  for  the  aorta  and  that  for  the  oesophagus. 

The  phrenic  arteries  ascend  along  the  lesser  muscle  of  the  dia- 
phragm, and  give  some  ramifications  to  it  and  to  the  capsulse  re- 
nales.  They  then  divide  each  into  two  leading  trunks,  which  are 
distributed  over  the  diaphragm,  principally  on  its  concave  surface. 
Some  small  ramifications  from  them  go  to  the  liver  and  to  the  lower 
part  of  the  oesophagus. 

The  two  phrenic  arteries  anastomose  with  each  other : also,  with 


* Anat.  Atlas,  Figs.  462  to  465,  inclusive. 


BRANCHES  OF  THE  ABDOMINAL  AORTA. 


257 


the  superior  phrenics,  coming  from  the  internal  mammary  ; and  with 
the  intercostals.  Sometimes  one  or  both  of  them  come  from  the 
cceliac  artery,  or  its  branches. 

The  Cceliac  Artery  (Arteria  Coeliaca)  is  the  next  branch  of  the 
abdominal  aorta,  and  arises  immediately  below  the  phrenics,  between 
the  crura  of  the  diaphragm,  opposite  the  junction  of  the  last  dorsal 
with  the  first  lumbar  vertebra.  It  is  a very  large  trunk,  and  goes 
off  at  right  angles,  being  placed  between  the  left  lobe  of  the  liver  and 
the  superior  margin  of  the  pancreas.  When  it  is  only  half  an  inch 
long,  it  is  split  into  three  trunks,  the  Gastric,  the  Hepatic,  and  the 
Splenic;  this  division  is  the  Tripus  Halleri. 

The  Gastric  Artery  ( Arteria  Gastrica,  Coronaria  Ventriculi)  is 
the  smallest  of  the  three  trunks,  and  frequently  arises  from  one  of 
the  others.  It  advances  forwards  and  towards  the  cardiac  orifice  in 
order  to  reach  the  small  curvature  of  the  stomach,  the  course  of 
which  it  pursues  to  the  pylorus,  between  the  two  laminae  of  the 
smaller  omentum.  It  gives  off  the  following  branches 

a.  Ramifications  to  the  oesophagus,  some  of  which  ascend  along 
it  into  the  posterior  mediastinum,  and  anastomose  there  with  the 

• similar  branches  coming  from  the  aorta;  others  go  transversely,  so 
as  to  surround  the  cardia,  reach  the  greater  end  of  the  stomach,  and 
anastomose  with  the  vasa  brevia. 

b.  The  ramifications  to  the  stomach  are  abundant,  but  of  an  in- 
determinate number,  and  arising  along  its  lesser  curvature,  are  dis- 
tributed in  winding  branches  to  the  anterior  and  the  posterior  sur- 
faces of  this  viscus,  between  its  membranes. 

c.  Not  unfrequently  the  artery  which  supplies  the  left  lobe  of  the 
liver  is  a branch  from  the  gastric,  in  which  case  the  latter  is  much 
larger  than  usual. 

2.  The  Hepatic  Artery  ( Arteria  Hepatica)  is  generally  consider- 
ably larger  than  the  gastric,  and  inclines  towards  the  right  side,  in 
order  to  reach  the  liver,  which  it  does  through  the  capsule  of  Glisson. 
It  sends  off  the  following  branches  : — 

a.  The  Right  Gastric  or  Gastro-Epiploic  Artery  ( Arteria  Gas- 
trica Dextra)  comes  from  it  near  the  pylorus,  and  descending  be- 
tween the  duodenum  and  pancreas,  reaches  the  greater  curvature 
of  the  stomach,  to  the  right  half  of  which,  and  to  the  correspond- 

Vol.  II.— 23 


•258 


CIRCULATORY  SYSTEM. 


ing  part  of  the  great  omentum,  it  is  distributed.  In  the  early  part 
of  its  course,  the  right  gastric  detaches  some  small  ramifications  to 
the  pylorus  (arteries  pylorica ;)  also,  to  the  duodenum  and  to  the 
pancreas  (art.  pancreatico-duodenales.)  The  latter  communicate,  by 
very  free  anastomoses,  with  the  superior  mesenteric  artery. 

After  having  sent  off  this  branch,  the  hepatic  artery  advances  to 
the  transverse  fissure  of  the  liver,  in  front  of  and  to  the  left  of  the 
vena  portarum.  It  then  divides  into  a right  and  a left  branch. 
The  former  sends  off  a ramification  to  the  gall-bladder,  (Art.  Cys- 
tica,) which  first  reaches  its  neck,  and  is  distributed,  by  many  arte- 
rioles, upon  the  parietes  of  this  reservoir  ; the  right  branch  then 
penetrates  deeply  into  the  transverse  fissure,  and  is  distributed  by 
many  ramifications,  throughout  the  right  lobe  of  the  liver.  The  left 
branch  of  the  hepatic  artery  is  distributed,  in  the  same  manner, 
throughout  the  left  lobe  of  the  liver. 

3.  The  Splenic  Artery  ( Arteria  Splenica ) is  larger  in  the  adult 
than  either  of  the  other  two  branches  of  the  coeliac,  and  goes  to  the 
spleen  along  the  superior  margin  of  the  pancreas,  performing,  in  this 
course,  several  considerable  flexuosities.  It  gives  off  the  following 
branches : — 

a.  The  Pancreatic  Arteries,  (Art.  Pancreatica  Medice  et  Sinistra) 
come  successively  from  its  inferior  margin,  as  it  goes  along  the  pan- 
creas. Their  number  and  size  are  variable,  but  commonly  they  are 
not  bigger  than  a knitting  needle  ; they  penetrate  perpendicularly 
into  the  pancreas,  and  then  subdivide  minutely  in  furnishing  its 
structure. 

b.  The  Left  Gastric  Artery  (Art.  Gastrica  Sinistra , Gastro-epi- 
ploica  Sinistra)  comes  from  the  left  extremity  of  the  splenic,  and  is 
about  the  same  size  with  the  right  gastric  artery,  but  sometimes 
larger.  It  attaches  itself  to  the  left'  extremity  of  the  stomach,  and 
goes  along  the  left  half  of  its  greater  curvature,  terminating  by  an 
anastomosis  with  the  right  gastric  artery.  In  this  course,  it  detaches 
ramifications  to  the  front  and  to  the  back  of  the  stomach,  and  to  the 
omentum  majus. 

c.  The  Short  Vessels  (Vasa  Brevia,  Art.  Gastrica.  Breves ) come 
from  the  splenic,  immediately  before  it  enters  the  spleen,  and  after 
it  has  subdivided  for  that  purpose.  They  are  five  or  six  in  number, 
and  are  distributed  upon  the  greater  extremity  of  the  stomach,  be- 
tween the  cardia  and  the  left  gastric  artery.  The  anastomoses 


BRANCHES  OF  THE  ABDOMINAL  AORTA. 


259 


between  the  several  arteries  of  the  stomach  are  so  free,  that  a fine 
injection  pushed  into  one,  readily  finds  its  way  into  all  the  others. 

The  splenic  artery,  when  it  gets  to  the  left  end  of  the  pancreas,  is 
divided  into  a cluster  of  branches,  and  in  that  condition  enters  the 
fissure  of  the  spleen,  throughout  the  interior  of  which  it  is  divided 
into  innumerable  ramifications. 

The  Superior  Mesenteric  Artery  (Arteria  Mesenterica  Superior ) 
arises  from  the  aorta,  while  the  latter  is  still  engaged,  between  the 
crura  of  the  diaphragm.  It  is  about  the  same  size  as  the  cceliac,  and 
comes  off  half  an  inch  below  it.  It  is  distributed  to  all  the  small 
intestines  and  to  the  right  side  of  the  large  one  after  the  following 
manner:  it  first  passes  behind  the  pancreas,  and  then  in  front  of  the 
duodenum,  to  reach  the  root  of  the  mesentery,  between  the  two  la- 
minae of  which  it  divides  and  subdivides  into  several  series  of  arches, 
one  after  another : they  become  successively  smaller  and  more  nu- 
merous till  they  reach  the  margin  of  the  intestine,  where  they  cease 
by  sending  a great  many  small  parallel  branches. 

The  trunk  of  the  superior  mesenteric  artery,  in  descending  be- 
tween the  lamina  of  the  mesentery,  describes  a considerable  curva- 
ture, the  convexity  of  which  is  to  the  left  side  and  downwards,  while 
its  concavity  is  in  a contrary  direction.  It  is  from  the  convexity  of 
this  trunk,  that  from  fifteen  to  twenty  large  branches  are  sent  ofif  suc- 
cessively to  form  the  roots  of  the  first  row  of  arterial  arches.  These 
branches  are  shorter,  and  generally  somewhat  smaller,  the  lower 
down  they  arise , and  their  origins  very  closely  succeed  each  other. 
Upon  the  first  row  of  arches  or  anastomoses  is  formed  a second  more 
numerous  and  small,  and  upon  the  second  row  is  formed  a third  still 
more  numerous  and  small,  from  which  proceed  the  intestinal  branches. 

Besides  the  preceding  branches,  the  superior  mesenteric  artery 
sends  off  the  following : 

Near  its  root  several  small  ramifications  arise,  which  go  to  the 
duodenum  and  to  the  pancreas,  and  anastomose  there  with  the  other 
arteries  supplying  the  same  organs. 

From  about  the  middle  of  the  concavity  of  the  superior  mesen- 
teric artery,  arise  the  three  Colic  arteries  called  Ileo-colica,  Colica 
Dextra,  and  Colica  Media : the  first  supplies  a cluster  of  branches 
to  the  lower  part  of  the  ileum  and  to  the  head  of  the  colon,  anasto- 
mosing on  the  left  with  the  last  of  the  small  intestinal  arteries  and 
on  the  right  with  the  colica  dextra:  the  Colica  Dextra  is  smaller 


260 


CIRCULATORY  SYSTEM. 


than  either  of  the  other  two  branches,  and  going  between  the  laminae 
of  the  mesocolon,  supplies  the  ascending  portion  of  the  colon  by 
dividing  into  two  principal  branches,  one  of  which  anastomoses 
with  the  ileo-colic  artery,  and  the  other  with  the  colica  media : the 
Colica  Media,  situated  between  the  laminae  of  the  transverse  meso- 
colon, and  arising  higher  up  than  the  colica  dextra,  advances  for- 
wards and  divides  into  two  principal  trunks ; one  of  which  supplies 
that  part  of  the  colon  in  the  right  hypochondriac  region,  and  the 
other  the  remainder  of  its  transverse  portion,  forming  an  anasto- 
mosis with  the  colica  superior  of  the  inferior  mesenteric  artery. 
The  arteries  which  supply  the  colon  differ  from  those  supplying  the 
small  intestines,  in  forming  but  one  row  of  arches  ; which,  in  fact, 
are  produced  by  the  anastomoses  spoken  of,  and  have,  therefore,  ex- 
tremely large  meshes.  From  the  convexity  of  these  arches,  many 
parallel  branches  run  out  to  supply  the  colon,  and  are  very  minutely 
distributed  to  it. 

The  Capsular  Arteries,  the  Emulgents,  and  the  Spermatics,  arise 
from  the  aorta,  between  the  superior  and  the  inferior  mesenteric. 
But  they  will  be  described  after  the  inferior  mesenteric,  so  as  to 
keep  together  the  account  of  the  arteries  of  the  intestines. 

The  Inferior  Mesenteric  Artery,  ( Art . Mesenterica  Inferior)  gene- 
rally arises  about  one  inch  above  the  division  of  the  aorta  into  the 
two  primitive  iliacs,  and  is  much  smaller  than  the  superior  Mesen- 
teric. It  inclines  downwards  to  the  left  side,  and  gets  between  the 
laminm  of  the  mesocolon  ; it  then  divides  into  three  branches,  called 
the  Left  Colic  Arteries,  from  their  distribution  to  the  left  side  of  the 
colon.  From  their  relative  situation  to  each  other,  they  are  distin- 
guished into  the  Superior,  the  Middle,  and  the  Inferior;  sometimes, 
however,  there  are  but  two  of  these  trunks. 

The  Superior  Colic  (Art.  Colica  Sinistra  Superior)  goes  horizon- 
tally towards  the  colon  in  the  left  lumbar  region;  having  got  near 
the  intestine  it  divides  into  two  branches,  one  of  which  ascends  to 
the  transverse  colon  to  form  the  anastomosis  with  the  Colica  Media 
of  the  upper  mesenteric,  while  the  other  descends  to  unite  with  the 
colica  media  sinistra.  The  Middle  Colic  Artery  (Art.  Colica  Sin- 
istra Media ) is  sometimes  a branch  of  the  superior,  and  is  occasion- 
ally wanting;  it  goes  towards  the  upper  part  of  the  sigmoid  flexure 


BRANCHES  OF  THE  ABDOMINAL  AORTA. 


261 


of  the  colon,  and  then  bifurcates:  one  branch  ascends  to  form  by 
anastomosis  an  arch  with  the  superior  colic,  while  the  other  branch 
descends  to  join  the  lower  colic  artery.  The  Inferior  Colic  Artery 
{Art.  Colica  Sinistra  Inferior ) goes  towards  the  middle  of  the  sigmoid 
flexure  of  the  colon,  and  there,  like  the  preceding,  divides  into  two 
branches;  one  anastomoses  with  the  artery  above,  while  the  other 
joins  with  the  arteries  which  go  to  the  rectum  from  the  inferior 
mesenteric. 

The  Superior  Hemorrhoidal  Artery  {Art^Hcemorrhoidea  Superior , 
Interna ,)  is  the  lowest  and  the  last  branc^HKe  inferior  mesenteric. 
It  descends  between  the  laminae  of  the  mes^Tc^n,  and  is  resolved 
into  two  symmetrical  trunks,  which  radiate  bj^jmviding  and  sub- 
dividing on  the  side  of  the  rectum,  and  are  dispersed  in  very  fine 
and  numerous  branches  throughout  its  substance.  It  anastomoses 
with  the  middle  and  the  inferior  haemorrhoidal  arteries,  also  with 
the  lateral  sacral. 

The  Capsular  Arteries  {Art.  Capsulares ) arise  frequently  from  the 
aorta  just  below  the  superior  mesenteric;  but  quite  as  often,  if  not 
more  so,  from  the  emulgents.  They  are  not  larger  than  a crow’s 
quill,  and  vary  from  one  to  three  on  either  side;  generally  howrever 
not  exceeding  one:  and  when  they  do,  they  are  proportionably 
small.  Passing  horizontally  outwards,  they  divide  into  several 
small  ramifications,  which  terminate  in  the  capsulce  renales.  Some 
of  their  branches  go  to  the  lesser  muscle  of  the  diaphragm. 

The  Em ul gent  Arteries  {Art.  Emulgentes , Renales ,)  are  two  in 
number,  one  for  each  kidney,  but  sometimes  more.  They  are  large 
but  short;  arise  from  the  side  of  the  aorta  immediately  below  the 
superior  mesenteric,  and  pass  outwardly  in  a horizontal  direction. 
The  right  one  is  longer  than  the  left,  somewhat  lower  down,  and 
passes  behind  the  ascending  cava.  They  are  both,  in  their  course, 
from  the  aorta  to  the  kidney,  covered  in  front  by  the  emulgent  vein, 
and  have  to  pass  through  a mass  of  adipose  matter. 

The  emulgent  sends  off  some  fine  ramifications  to  the  adipose 
matter,  which  surrounds  it,  and  before  it  reaches  the  fissure  of  the 
kidney  divides  into  three  or  four  branches,  preparatory  to  its  intro- 
duction into  this  gland,  upon  the  structure  of  which  it  is  ultimately 
distributed  by  very  fine  branches. 

23s5 


■262 


CIRCULATORY  SYSTEM. 


The  Spermatic  Arteries  (Arteria  Spermatic# , Seminales,)  arise 
from  the  aorta  somewhat  below  the  emulgents,  but  in  some  cases 
from  the  latter  themselves.  They  are  two  in  number,  one  on  each 
side,  and  are  about  the  size  of  a crow  quill  in  the  male  subject,  but 
smaller  in  the  female.  One  comes  off  generally  higher  up  than  the 
other;  they  then  descend  on  the  sides  of  the  vertebral  column  before 
the  psoae  muscles,  and  cross  in  front  of  the  ureters,  being  in  all  this 
course  behind  the  peritoneum.  They  are  tortuous,  and  shortly  after 
their  origin  begin  to  adhere  to  the  spermatic  veins,  which  adhesion 
is  continued  to  the  testicle. 

The  branches  that  the  spermatic  artery  sends  off  in  the  abdomen 
are  inconsiderable,  consisting  in  very  fine  twigs  to  the  adjacent 
adipose  matter,  to  the  lymphatic  glands,  to  the  ureter,  and  to  the 
peritoneum.  In  the  male  subject  it  passes  with  the  vas  deferens, 
through  the  abdominal  canal,  and  reaching  the  testicle  divides  into 
branches  which  supply  the  body  of  this  gland  and  the  epididymis. 
In  descending  from  the  external  ring  to  the  testis,  some  small  rami- 
fications, to  the  adjacent  parts,  leave  it.  In  the  female,  the  sper- 
matic artery  does  not  leave  the  cavity  of  the  abdomen,  but,  de- 
scending into  the  pelvis,  gets  between  the  laminae  of  the  broad 
ligament  to  the  ovarium,  and  is  spent  principally  upon  the  latter. 
Some  of  its  branches  go  to  the  Fallopian  Tube,  to  the  Round  Liga- 
ment of  the  uterus,  and  to  the  sides  of  the  latter,  where  they  anas- 
tomose with  the  uterine  arteries.* 

The  Lumbar  Arteries  ( Arterice  Lumbares ) are  commonly  five  in 
number  on  either  side,  but  seldom  less  than  three,  and  in  their  course 
outwards,  correspond  with  the  intercostal  arteries.  They  are  much 
larger  than  the  latter.  They  arise  in  pairs  from  the  posterior  external 
face  of  the  aorta,  at  a point  corresponding  with  the  middle  of  the 
bodies  of  the  four  upper  lumbar  vertebrae,  and  pass  outwards  be- 
tween the  fasciculi  of  the  psoas  magnus  muscle,  to  which,  to  the 
quadratus  lumborurn,  and  the  bodies  of  the  vertebrae,  they  distribute 
several  branches.  Sometimes  each  pair  arises  by  a common  trunk 
from  the  posterior  face  of  the  aorta.  As  the  latter  terminates  at  the 
fourth  lumbar  vertebra,  the  fifth  lumbar  artery  is  a branch  from  the 
fourth  in  most  instances. 

* The  spermatic  artery  is  spindle-shaped,  the  smallest  end  being'  the  origin ; 
this  favours  the  flow  of  blood  in  it,  which  would  otherwise  suffer  from  so  much 
friction, 


BRANCHES  OF  THE  ABDOMINAL  AORTA.  263 

At  the  base  of  the  transverse  process  each  artery  divides  into  two 
branches,  a posterior  or  dorsal  one,  and  an  anterior  or  lumbar. 
The  dorsal  branch,  which  is  smaller  than  the  other,  detaches  a ra- 
mification through  the  intervertebral  foramen  to  the  lower  part  of  the 
medulla  spinalis  and  to  the  cauda  equina:  it  then  gets  to  the  back, 
where  it  is  spent  upon  the  muscles  near  the  spine.  The  anterior 
lumbar  branch  advances  between  the  broad  muscles  of  the  abdomen 
to  which  it  is  distributed  ; and  runs  forwards  far  enough  to  anasto- 
mose with  the  epigastric  artery. 

The  first  lumbar  artery  is  the  smaller,  and  sometimes  comes  from 
the  last  intercostal : it  goes  a little  below  the  inferior  margin  of  the 
last  rib,  and  then  descends  almost  vertically  between  the  peritoneum 
and  the  transversalis  abdominis  muscle.  The  lower  lumbar  arteries 
anastomose  with  the  circumflexa  ilii,  and  with  the  superficial  branches 
of  the  gluteal. 

The  Middle  Sacral  Artery  (Arteria  Sacra  Media ) is  generally  not 
so  large  as  a lumbar;  it  arises  from  the  centre  of  the  bifurcation  of 
the  aorta  into  the  two  primitive  iliacs,  or  else  a line  or  two  above  it, 
behind.  It  descends,  in  front  of  the  middle  line  of  the  fifth  lumbar 
vertebra  and  of  the  sacrum,  to  the  coccyx  adhering  to  the  surface  of 
these  bones,  and  performing  some  flexuosities. 

It  sometimes  happens  that  the  last  pair  of  lumbar  arteries  comes 
from  it,  or  at  least  one,  according  to  Meckel,  more  commonly  the 
left:  in  which  case  the  sacral  is  of  unusual  size.  The  sacral  after- 
wards sends  off,  to  the  right  and  left,  a pair  of  branches  for  each 
pair  of  sacral  foramina.  They  run  across  the  sacrum,  send  branches 
to  it,  anastomose  with  the  lateral  sacral  arteries,  and  then  penetrate 
to  the  cauda  equina.  The  middle  sacral  artery  is  lost  at  the  inferior 
end  of  the  coccyx,  in  the  fat  and  cellular  tissue  of  the  part. 


SECT.  VI. — OF  THE  PRIMITIVE  ILIAC  ARTERIES,  AND  THEIR 
BRANCHES.  * 

The  Primitive  Iliac  Arteries,  [Art.  Iliacce  Primitivcc  communes ,) 
one  on  each  side,  are,  as  mentioned,  the  terminating  trunks  of  the 
abdominal  aorta.  They  extend  from  the  lower  part  of  the  fourth 


* Anat.  Atlas,  Fig.  465. 


264 


CIRCULATORY  SYSTEM. 


lumbar  vertebra  to  the  sacro-iliac  junction,  or  near  it,  where  they 
divide  into  two  trunks,  the  Internal  and  the  External  Iliac.  This 
division  however  not  unfrequently  occurs  at  the  inferior  lateral  edge 
of  the  fifth  lumbar  vertebra,  near  the  base  of  the  sacrum. 

The  primitive  iliac  is  bounded  on  the  outer  side  by  the  psoas 
magnus  muscle,  and  behind  by  the  primitive  iliac  vein ; it  is  crossed 
at  its  lower  part  by  the  ureter.  No  branches  deserving  of  especial 
notice  are  sent  from  it  before  it  bifurcates;  such  as  exist  are  very 
small,  and  go  simply  to  the  parts  immediately  contiguous.  The 
right  artery  crosses  in  front  of  the  root  of  the  left  iliac  vein. 


SECT.  VII. — OF  THE  INTERNAL  ILIAC,  OR  THE  HYPOGASTRIC 

ARTERY.* 

The  Internal  Iliac  Artery  (Art.  lliaca  Interna , Hypogastrica ) 
descends  from  its  origin  near  the  front  upper  part  of  the  sacro-iliac 
junction,  to  the  lower  part  of  the  same  articulation.  In  this  descent, 
it  is  bounded  behind  by  the  sacral  plexus  of  nerves,  and  gives  off 
several  arterial  trunks ; but  the  manner  by  which  the  last  is  accom- 
plished is  much  varied  in  different  subjects.  For  the  most  part,  it 
is  an  inch  or  more  long  before  any  important  branches  leave  it ; it 
is  then  frequently  divided  into  two  principal  trunks,  an  anterior  and 
a posterior,  from  which  proceed  the  several  branches  that  supply 
the  internal  and  the  external  parts  of  the  pelvis.  The  rule  of  ori- 
gin of  the  secondary  trunks  from  these  two  principal  ones,'  even 
when  the  latter  exist,  is  not  fixed ; for  sometimes  they  arise  from 
one,  sometimes  from  the  other,  and  then  again  from  the  trunk  of 
the  hypogastric  itself. 

The  Ilio-Lumbar  Artery  (Art.  Ilio  Lumbaris ) is  commonly  the 
first  branch  of  the  hypogastric,  or  of  its  posterior  trunk.  It  ascends 
outwards  and  backwards  behind  the  psoas  magnus  muscle,  and 
there  divides  into  two  branches,  a superior  and  an  inferior.  The 
former  continues  to  ascend  between  the  psoas  magnus  and  the  iliacus 
interims  muscle,  to  which,  and  to  the  quadratus  lumborum,  it  dis- 
tributes branches:  it  also  sends  ramifications  into  the  spinal  cavity, 
and  anastomoses  with  the  lower  lumbar  arteries  ; sometimes  it  sup- 

* Anat.  Atlas,  Figs.  469  to  472,  inclusive. 


INTERNAL  ILIAC  ARTEKY,  AND  ITS  BRANCHES,  265 

plies  the  place  of  the  last  lumbar  entirely.  The  inferior  branch 
going  outwardly,  is  divided  into  two  orders  of  ramifications  which 
supply  the  iliacus  internus  muscle,  on  its  surface  and  more  deeply  ; 
also  the  os  ilium  by  a ramuscule  which  penetrates  the  nutritious  fora- 
men of  the  latter.  The  inferior  branch  anastomoses  with  the  cir- 
cumflexa  ilii  of  the  external  iliac. 

The  Lateral  Sacral  Arteries  ( Arteries  Sacra  Laterales ) arise  next, 
either  from  the  hypogastric  or  from  its  posterior  trunk  : their  number 
is  commonly  equal  to  that  of  the  foramina  on  the  side  of  the  sacrum  in 
front,  though  they  may  come  from  only  one  or  two  roots.  They 
cross  in  front  of  the  sacrum,  and  divide  into  branches,  some  of  which 
anastomose  with  the  middle  sacral  artery,  while  others  enter  the 
foramina  of  the  sacrum,  to  be  spent  on  the  lower  part  of  the  cauda 
equina. 

The  Obturator  Artery  ( Arteria  Obturatoria ) comes  commonly  from 
the  hypogastric  or  from  one  of  its  principal  trunks  ; in  some  cases  it 
arises  from  the  epigastric  or  from  the  external  iliac,  near  Poupart’s 
ligament.  In  the  first  cases  it  passes  forwards  parallel  with  the 
brim  of  the  pelvis,  and  in  the  latter  cases  it  descends  behind  the 
superior  ramus  of  the  pubes.  Whatever  may  be  the  condition  of  its 
origin,  it  gets  from  the  pelvis  through  the  upper  part  of  the  thyroid 
foramen  over  the  superior  margin  of  the  obturator  internus  muscle, 
having  previously  sent  off  some  inconsiderable  ramifications  to 
the  periosteum  and  the  contiguous  muscles  within  the  pelvis. 

It  emerges  from  the  pelvis  on  the  upper  margin  of  the  obturator 
externus  muscle,  and  then  divides  into  two  principal  trunks.  The 
posterior  descends  along  the  external  margin  of  the  obturator  ex- 
ternus muscle,  to  which  it  gives  ramifications  ; it  likewise  sends 
some  branches  to  the  heads  of  the  muscles  coming  from  the  tuber 
of  the  ischium,  and  thereby  anastomoses  with  the  sciatic  artery : 
other  branches  are  spent  upon  the  hip  joint,  one  of  which  gets  into 
the  cavity  of  the  latter  through  the  notch  at  the  lower  part  of  the 
acetabulum,  and  is  spent  upon  the  adipose  matter  in  its  bottom. 
The  anterior  branch  goes  to  the  heads  of  the  adductor  muscles,  to 
the  pectineus,  to  the  obturator  externus,  and  to  the  integuments  of 
the  upper  internal  part  of  the  thigh.  Near  its  origin  this  branch 
sends  a ramification  along  the  internal  margin  of  the  thyroid  fora- 


266 


CIRCULATORY  SYSTEM. 


men  to  anastomose  Avith  the  posterior  branch,  so  that  the  foramen, 
is  surrounded  by  an  arterial  circle. 

The  Middle  Haemorrhoidal  Artery  [Art.  Hcemorrhoidea  Media) 
varies  in  its  origin,  being  sometimes  from  the  hypogastric  itself  and, 
on  other  occasions,  from  one  of  its  branches,  as  the  gluteal,  ischiatic, 
&c.  It  descends  on  the  fore  part  of  the  rectum,  opposite  the 
loAver  fundus  of  the  bladder  in  the  male,  and  is  distributed  by 
branches  to  the  rectum,  to  the  vesicula  seminalis,  and  to  the  pros- 
tate gland.  In  the  female  it  dispenses  branches  to  the  vagina.  It 
is  called  middle,  from  its  position  betAveen  the  upper  and  the  loAver 
haemorrhoidal  arteries. 

In  both  sexes,  the  branches  which  it  sends  to  other  parts  besides 
the  rectum,  frequently  arise  from  other  arteries,  and  in  a man- 
ner which  causes  them  to  have  distinct  appellations,  as  vaginal,  &c. 

The  Vesical  Arteries  [Arteries  Vesicates)  consist  in  several  rami- 
fications, coming  from  Avhat  was  the  umbilical  artery  of  the  foetus, 
but  which,  in  the  adult,  with  the  exception  of  a short  space  near  its 
origin,  is  converted  into  a ligamentous  chord.  These  branches 
ramify  upon  the  parietes  of  the  bladder ; one  of  them  more  volumi- 
nous than  any  other,  and  called,  by  M.  Chaussier,  Aresico-prostatic, 
gains  the  lower  fundus  of  the  bladder ; sends  branches  to  it,  to  the 
prostate,  to  the  vesicula  seminalis,  and  to  the  commencement  of  the 
urethra. 

The  Uterine  Artery  [Arteria  Uterina ) arises  from  the  hypogastric, 
or  one  of  its  branches,  near  the  vesical,  sometimes  before,  and  on 
other  occasions  subsequent  to  them.  Being  peculiar  to  the  female 
sex,  its  size  varies  according  to  the  individual  being  in  a state  of 
pregnancy  or  not : in  the  latter  stages  of  gestation  it  is  as  large  as 
any  other  branch  of  the  hypogastric. 

It  goes  inwards  toAvards  the  superior  part  of  the  vagina,  to  which 
it  gives  some  ramifications  ; it  then  ascends  between  the  laminae  of 
the  broad  ligament,  in  a tortuous  manner  along  the  side  of  the  uterus, 
and  divides  into  many  branches  which  are  distributed  through  the 
tissue  of  this  organ.  It  anastomoses  with  the  corresponding  arteries 
of  the  other  side,  and  with  the  branches  of  the  spermatic  artery  which 
go  to  the  Fallopian  tube  and  to  the  ovarium. 

Besides  the  preceding,  the  Hypogastric,  or  Internal  Iliac  artery 


INTERNAL  ILIAC  ARTERY,  AND  ITS  BRANCHES. 


267 


sends  off  two  large  branches,  the  Gluteal  and  the  Ischiatic,  which 
terminate  it.  In  many  subjects  they  are  the  direct  continuation  of 
the  two  primitive  trunks,  into  which  the  hypogastric  is  frequently 
originally  divided. 

The  Gluteal  Artery,  ( Arteria  Glutea ,)  shortly  after  its  origin, 
issues  from  the  pelvis  above  the  pyriformis  muscle,  at  the  upper  part 
of  the  ischiatic  foramen,  where  it  adheres  closely  to  the  edge  of  the 
bone.  When  it  first  gets  to  the  dorsum  of  the  ilium,  it  is  covered 
by  the  gluteus  magnus  muscle,  and  lies  at  the  posterior  margin  of 
the  gluteus  minimus,  precisely  under  a line  drawn  from  the  posterior 
superior  spinous  process  to  the  top  of  the  trochanter  major.  It 
almost  immediately  afterwards  divides  into  two  principal  trunks. 

One  of  these  trunks,  the  more  superficial,  advances  between  the 
gluteus  medius  and  the  magnus,  and  distributes  branches  to  them ; 
also,  to  the  posterior  margin  of  the  magnus,  where  it  comes  from 
the  posterior  sacro-sciatic  ligament.  The  more  deeply-seated  trunk 
goes  forwards  between  the  gluteus  medius  and  minimus,  and  sub- 
divides into  three  orders  of  branches  for  their  supply.  One  set 
follows  the  superior  margin  of  the  gluteus  minimus  towards  the 
anterior  superior  spinous  process ; another  set  passes  nearer  the 
middle  of  the  gluteus  minimus ; and  the  third  set  still  lower  down 
upon  the  dorsum  of  the  ilium,  above  the  acetabulum ; some  of  the 
ramifications  go  to  the  capsular  ligament  of  the  joint,  where  they 
anastomose  with  branches  from  the  femoral  artery. 

The  Ischiatic  Artery  ( Arteria  Ischiadica ) is  somewhat  smaller  than 
the  gluteal,  but  looks  rather  more  like  the  continuation  of  the  hypo- 
gastric. It  descends  between  the  rectum  and  the  pyriformis  muscle, 
and  issues  under  the  lower  margin  of  the  latter,  out  of  the  pelvis, 
being  there  placed  in  front  of  the  sciatic  nerve.  It  goes  downwards 
on  the  back  of  the  thigh,  between  the  trochanter  major  and  the 
tuberosity  of  the  ischium,  being  at  the  internal  edge  of  the  sciatic 
nerve,  and  on  the  posterior  face  of  the  small  rotator  muscles  of  the 
thigh.  It  sends  off  in  the  pelvis  the  internal  Pudic  Artery,  and  also 
some  inconstant  branches,  of  small  size,  to  the  viscera  within  the 
pelvis;  when  it  has  emerged  from  the  latter,  it  detaches  some  con- 
siderable branches  to  the  origin  and  to  the  inferior  margin  of  the 
gluteus  magnus  muscle,  and  to  the  small  rotator  muscles.  The 
branch  which  may  be  considered  as  the  continued  trunk  of  the 


•268 


CIRCULATORY  SYSTEM. 


ischiatic,  descending  on  the  posterior  face  of  the  thigh,  along  with 
the  sciatic  nerve,  under  the  hamstring  muscles,  is  lost  in  ramifica- 
tions to  them,  and  by  anastomoses  with  the  perforating  arteries. 

The  Internal  Pudic  Artery,*  ( Arteria  Pudica  Interna ,)  though  a 
branch  of  the  ischiatic,  is  only  in  a slight  degree  smaller.  It  arises 
a little  above  the  spinous  process  of  the  ischium,  in  the  pelvis,  in 
front  of  the  sciatic  plexus,  and  getting  from  the  pelvis  between  the 
anterior  sacro-sciatic  ligament  and  the  inferior  margin  of  the  pyri- 
formis  muscle,  it  passes  over  the  posterior  face  of  the  anterior  sacro- 
sciatic  ligament,  at  the  spinous  process  of  the  ischium.  It  imme- 
diately afterwards  returns  into  the  cavity  of  the  pelvis,  between  the 
two  sacro-sciatic  ligaments,  at  the  place  where  the  obturator  internus 
muscle  winds  over  the  ischium ; it  then  goes  along  the  internal  face 
of  the  latter  bone  and  of  its  ascending  ramus,  at  the  inferior  margin 
of  the  obturator  internus  muscle  ; and  continues  on  the  internal  face 
of  the  ramus  of  the  pubes,  between  the  two  laminae  of  the  triangular 
ligament,  above  the  crus  of  the  penis  to  the  symphysis  of  the  pubes. 

In  this  course  the  Internal  Pudic  Artery  detaches  several  impor- 
tant branches,  in  the  following  order  : — 

a.  A ramification  along  the  inferior  margin  of  the  pyriformis,  to 
tills  muscle  and  to  the  parts  on  the  posterior  face  of  the  neck  of  the 
os  femoris,  where  it  anastomoses  with  the  other  arteries  of  this  re- 
gion. 

b.  The  Lower  Haemorrhoidal  Artery  [Art.  Ilcemorrhoidea  Inferior , 
Externa ) to  the  inferior  part  of  the  rectum,  and  to  the  external 
sphincter  ani  muscle.  This  artery  arises  after  the  internal  pudic 
has  returned  within  the  pelvis,  and  consists  sometimes  in  several 
branches. 

c.  The  Perineal  Artery  {Art.  Perinea , Transversa  Perinei ) has 
its  root  near  the  origin  of  the  transversus  perinei  muscle,  and  ad- 
vancing obliquely  forwards  is  distributed  in  several  ramifications  to 
the  muscles  and  integuments  of  the  perineum,  and  to  the  posterior 
part  of  the  scrotum.  It  is  unavoidably  cut  in  the  lateral  operation 
for  the  stone.  In  the  female  it  goes  to  the  sphincter  vaginae  and  to 
the  labium  externum. 

d.  When  the  internal  pudic  has  got  beyond  the  transversus  peri- 
nei muscle  near  the  beginning  of  the  crus  penis,  it  detaches  to  the 


* Anat.  Atlas.  Fig.  467. 


EXTERNAL  ILIAC  ARTERY,  AND  ITS  BRANCHES. 


269 


bulb  of  the  urethra,  along  the  posterior  margin  of  the  triangular  liga- 
ment, a branch  which  penetrates  to  the  corpus  spongiosum,  and  is 
minutely  distributed  upon  it,  some  of  its  ramifications  reaching  to 
the  corpus  cavernosum.  This  branch  is  called  by  M.  Chaussier, 
Urethro-bulbar,  and  instead  of  being  always  distinct,  it  on  some  oc- 
casions comes  from  the  Perineal. 

e.  At  the  under  part  of  the  symphysis  pubis,  between  it  and  the 
back  of  the  penis,  the  internal  pudic  sends  forwards,  on  the  dorsum 
of  the  penis,  a superficial  branch,  ( Ramus  Superficialis  Dorsi  Penis.) 
It  advances  to  the  end  of  the  penis,  under  the  skin,  being  parallel 
with  its  fellow  of  the  other  side,  and  near  to  it : sometimes  the  two 
unite  after  a short  course.  They  are  dispersed  in  branches  to  the 
integuments,  and  to  the  elastic  ligament  of  the  penis. 

f The  Cavernous  Artery  of  the  Penis  (Art.  Cavernosa  Profunda 
Penis)  may  be  considered  as  the  terminating  trunk  of  the  internal 
pudic.  It  penetrates  the  corpus  cavernosum,  beneath  the  symphy- 
sis of  the  pubes,  and  quickly  divides  into  many  ramifications.  The 
latter  advance,  and  continue  to  subdivide  upon  the  cells  of  the 
corpus  cavernosum,  to  which  they  are  principally  distributed : some 
of  them  reach  the  corpus  spongiosum  urethras,  and  others  anastomose 
with  the  corresponding  arteries  of  the  other  side. 


SECT.  VIII. — OF  THE  EXTERNAL  ILIAC  ARTERY,  AND 
ITS  BRANCHES.* 

The  External  Iliac  Artery  (Arteria  lliaca  Externa)  extends  from 
the  bifurcation  of  the  primitive  iliac  to  Poupart’s  ligament,  where  it 
is  continued  to  the  lower  extremity  under  the  name  of  the  femoral 
artery.  It  looks  like  the  continuation  of  the  .primitive  iliac,  and  de- 
scends at  the  superior  strait  of  the  pelvis  along  the  internal  margin 
of  the  psoas  magnus  muscle.  In  the  early  part  of  its  course,  it  is 
anterior  to  the  external  iliac  vein ; it  then,  as  it  approaches  Poupart’s 
ligament,  gets  to  its  outer  margin.  It  is  covered  by  the  peritoneum 
in  front.  Where  it  passes  beneath  Poupart’s  ligament  to  the  thigh, 
it  is  about  half  way  between  the  anterior  superior  spinous  process  of 
the  ilium  and  the  symphysis  pubis,  having  the  vein  at  its  pubic 
margin  and  the  anterior  crural  nerve,  half  an  inch  from  its  iliac 

* Anat.  Atlas,  Figs.  466,  468. 

Vol.  II.— 24 


270 


CIRCULATORY  SYSTEM. 


margin.  No  branches  of  consequence  arise  before  it  reaches  the 
crural  arch  ; it  then  sends  of  two,  the  Epigastric  and  the  Circumflex 
Iliac  Artery. 

The  Epigastric  Artery  ( Jlrteria  Epigastrica ) arises  somewhat 
above  the  crural  arch,  at  the  line  where  the  peritoneum  is  reflected 
|rom  the  fascia  transversalis  upon  the  iliac  fascia.  It  at  first  passes 
horizontally  inwards,  then  rises  obliquely  upwards  and  inwards,  be- 
hind the  spermatic  chord,  at  the  pubic  margin  of  the  internal  abdo- 
minal ring.  Afterwards  it  reaches  the  external  margin  of  the  rectus 
abdominis  muscle,  two  or  three  inches  above  the  pubes:  ascending 
along  it  for  a short  distance,  it  then  passes  to  its  posterior  face,  and 
continues  ascending  above  the  umbilicus;  where  being  divided  into 
several  branches,  it  terminates  by  anastomosing  with  the  lower  ra- 
mifications of  the  internal  mammary  artery. 

This  artery  is  almost  entirely  spent  upon  the  anterior  parietes  of 
the  abdomen,  in  ramifications,  which  anastomose  with  the  last  in- 
tercostals  and  with  the  lumbar  arteries.  One  of  its  small  twigs, 
■called  the  External  Spermatic  artery,  following  the  course  of  the 
spermatic  chord,  or  of  the  round  ligament,  is  distributed  upon  the 
cremaster,  the  tunica  vaginalis,  and  the  scrotum  of  the  male,  and 
upon  the  inons  veneris  of  the  female.  In  some  cases  the  epigastric 
gives  off  the  obturator  artery  as  stated. 

The  Circumflex  Iliac  Artery  ( jlrteria,  Circumflexa  liii)  is  of  the 
same  size  with  the  epigastric,  and  comes  from  the  external  iliac, 
sometimes  on  a level  with  it,  and  on  other  occasions  lower  down, 
even  below  the  crural  arch.  It  ascends  outwardly  towards  the  an- 
terior superior  spinous  process  of  the  ilium,  along  the  posterior  mar- 
gin of  the  crural  arch,  and  following  afterwards  the  direction  of  the 
crista  of  the  ilium,  it  anastomoses  with  the  corresponding  branch  of 
the  ilio-lumbar  artery. 

The  following  branches  come  from  it.  In  the  early  part  of  its 
course  some  important  twigs  are  sent  to  the  adjacent  muscles,  as  the 
sartorius,  iliacus  interims  and  so  on.  At  the  anterior  superior 
spinous  process,  it  divides  into  two  branches;  the  smaller  ascends 
between  the  internal  oblique  and  the  transversalis  muscle,  and  is 
distributed  upon  them ; the  other  branch  which  is  the  continuation 
of  the  main  trunk  along  the  crista  of  the  ilium  at  the  margin  of  the 
iliacus  internus  muscle,  sends  ramifications  to  the  latter,  and  also 


FEMORAL  ARTERY,  AND  ITS  BRANCHES. 


271 


to  the  posterior  part  of  the  broad  muscles  of  the  abdomen,  where  it 
anastomoses  with  the  other  arteries  of  this  region. 


Of  the  Femoral  Artery  * 

The  Femoral  Artery  ( Arteria  Femoralis,  Cruralis ,)  the  continua- 
tion of  the  external  iliac,  extends  from  the  crural  arch  or  Poupart’s 
ligament,  to  a perforation  for  its  passage  through  the  adductor  mag- 
nus  muscle,  and  which  is  commonly  one-third  of  the  whole  length 
of  the  os  femoris,  above  the  knee  joint.  This  great  trunk,  imme- 
diately below  Poupart’s  ligament  is  very  superficial,  and  may  be 
felt  pulsating  where  it  passes  over  the  pubes.  It  is  there  covered 
only  by  the  common  integuments,  and  the  fascia  femoris,  which  is 
thin;  it  is  bounded  internally  by  the  femoral  vein,  externally  by  the 
crural  nerve  ; is  half-way  between  the  anterior  superior  spinous  pro- 
cess and  the  symphysis  of  the  pubes,  and  lies  upon  the  internal 
face  of  the  psoas  magnus  over  the  interstice  between  it  and  the 
pectineus.  In  the  upper  third  of  its  course  the  femoral  artery  is  at 
the  inner  edge  of  the  rectus  femoris,  and  at  a short  distance  from  it ; 
it  then  inclines  inwards,  and  occupies  the  angle  formed  by  the  ad- 
hesion of  the  vastus  internus  to  the  adductor  longus.  The  sartorius, 
at  first,  is  remote  at  its  outside,  but  this  muscle,  inclining  inwards  in 
its  descent  gets  to  the  exterior  margin  of  the  artery,  and  afterwards 
covers  it  completely  for  the  remainder  of  its  course.  The  femoral 
.artery  is  in  front  of  the  femoral  vein  when  it  has  descended  three 
or  four  inches  below  the  crural  arch;  behind  the  two  is  the  arteria 
profunda.  When  the  femoral  artery  and  vein  reach  the  angle 
formed  by  the  vastus  internus  and  the  adductor  longus,  they  are 
covered  by  a strong  interlacement  of  tendinous  fibres  from  these 
muscles. 

The  femoral  artery  sends  off  these  branches  : 

1.  The  Superficial  Artery  of  the  Abdomen  (Art.  ad  Cutem  Ab- 
dominis) is  small,  and  arises  at  the  lower  margin  of  Poupart’s  liga- 
ment: it  goes  upwards  towards  the  umbilicus,  beneath  the  fascia 
superficialis  abdominis,  and  is  distributed  to  the  integuments  of  this 
region.  One  of  its  ramifications  goes  to  the  inguinal  glands. 


* Anat.  Atlas,  Figs.  466,  469. 


272 


CIRCULATORY  SYSTEM. 


2.  The  External  Pudic  Arteries  (Art.  Pudenda  Externa ) come 
from  the  femoral  at  the  same  point-,  and  are  two  or  three  in  number ; 
they  are  of  small  size.  One  of  them  inclines  inwards  along  the 
groin,  between  the  skin  and  the  fascia  femoris,  and  is  distributed 
to  the  integuments  of  the  pubes,  to  those  of  the  penis,  and  to  the 
scrotum,  or  to  the  labium  externum  of  the  female.  The  second,  and 
the  third  when  it  exists,  are  rather  lower  down,  and  are  dispersed 
upon  much  the  same  region  by  branches  to  the  integuments.  The 
lymphatic  glands  of  the  groin  also  derive  their  supply  of  blood  from 
these  several  external  pudic  arteries. 

3.  The  Profound  Artery,  ( Arteria  Profunda  Femoris ,)  the  great 
muscular  artery  of  the  thigh,  is  but  slightly  inferior  in  size  to  the  fe- 
moral itself,  and  comes  from  the  latter  at  the  distance  of  from  one  or 
two  inches  below  the  crural  arch.  It  lies  behind  the  femoral  artery, 
and  descends  in  that  situation  between  the  insertion  of  the  adductor 
brevis  and  the  vastus  internus  muscle,  to  the  upper  part  of  the 
insertion  of  the  adductor  longus.  In  this  course  its  size  is  much 
diminished  by  the  origin  from  it  of  several  considerable  trunks  as 
follows : 

a.  The  External  Circumflex,  ( Arteria  Circumflexa  Externa ,) 
though  most  frequently  a branch  of  the  profunda,  sometimes  comes 
from  the  femoral  above  or  below  it  a short  distance.  It  goes  im- 
mediately outwards  between  the  rectus  femoris  muscle  and  the  cru- 
ralis,  giving  off  some  inconsiderable  ramifications.  While  between 
these  muscles  it  divides  into  two  branches,  one  of  which  ascends 
and  the  other  descends ; the  former  is  distributed  to  the  anterior 
margin  of  the  gluteus  medius  and  minimus,  to  the  capsule  of  the 
joint,  the  parts  about  the  trochanter  major,  and  anastomoses  with 
the  gluteal  and  the  ischiatic.  It  is  said  by  Meckel,  that  these  anas- 
tomoses have  been  found  much  dilated  where  the  external  iliac 
artery  has  been  taken  up.  The  descending  branch  is  about  the  size 
of  a crow  quill,  or  even  larger ; it  first  passes  obliquely  downwards 
between  the  rectus  femoris  and  the  cruralis,  it  then  descends  verti- 
cally under  the  anterior  margin  of  the  vastus  externus,  between  it 
and  the  cruralis,  to  terminate  at  the  knee,  where  it  becomes  super- 
ficial and  anastomoses  with  the  articular  arteries.  It  is,  how’ever, 
principally  distributed  to  the  vastus  externus  and  to  the  cruralis. 

b.  The  Internal  Circumflex  Artery  ( Arteria  Circumflexa  Interna ,) 
arises  from  the  profunda,  near  the  external  circumflex,  generally 


PROFOUND  ARTERY,  AND  ITS  BRANCHES.  273 

below  it,  but  sometimes  the  reverse  ; in  some  cases,  it  comes  from 
the  femoral  artery  itself,  near  the  crural  arch.  It  passes  transversely 
inwards,  and  dips  into  the  interstice  between  the  pectineus  and  the 
psoas  magnus,  after  having  given  off  some  small  twigs  to  the  heads 
of  the  adjoining  adductors.  It  then  winds  under  the  neck  of  the  os 
femoris  and  divides  into  two  branches ; the  upper  one  goes  to  the 
capsular  ligament  of  the  joint,  to  the  obturator  externus  muscle,  anas- 
tomoses with  the  obturator  artery,  and  sends  a branch  behind  the 
adductor  brevis  to  the  upper  part  of  the  adductor  magnus  : the  inferior 
branch  is  larger  than  the  other;  it  descends  behind  the  adductor 
magnus  and  is  distributed  in  branches  to  it,  to  the  gracilis,  and  to 
the  hamstring  muscles,  sending  upwards  some  ramifications  ( rami 
trochanterici ) to  the  parts  about  the  trochanter  major,  where  they 
anastomose  with  the  external  circumflex  artery. 

c.  Muscular  branches  of  inconstant  origin,  and  of  inconsiderable 
size,  are  sent  from  the  profunda  to  supply  the  anterior  face  of  the  ad- 
ductor muscles. 

d.  The  Perforating  Arteries  [Rami  Profundi  Perforantes ) obtain 
the  name  from  their  perforating  the  adductor  magnus,  which  they  do 
near  the  linea  aspera,  so  as  to  get  to  the  back  of  the  thigh.  They 
commonly  are  four  in  number,  and  as  they  come  off  successively 
from  the  profunda,  they  are  designated  numerically.  In  some  cases, 
however,  they  are  reduced  to  one,  by  being  concentrated  in  a com- 
mon trunk,  which  penetrating  high  up  the  adductor  magnus,  and 
afterwards  descending  on  its  posterior  face,  is  dispersed  upon  the 
muscles  on  the  back  of  the  thigh. 

The  First  Perforating  Artery  arises  somewhat  belowT  the  trochanter 
minor,  and  penetrates  the  adductor  magnus  a little  below  its  superior 
margin.  One  of  its  branches  ascends  towards  the  trochanter  major, 
where  it  anastomoses  with  the  external  circumflex  and  with  the 
gluteal,  while  another  descending  is  spent  upon  the  heads  of  the 
flexor  muscles  of  the  leg. 

The  Second  Perforating  Artery  gets  to  the  back  of  the  thigh,  at 
the  lower  magin  of  the  insertion  of  the  gluteus  magnus  into  the  linea 
aspera,  being  distributed  in  that  region,  and  to  the  corresponding 
portion  of  the  long  head  of  the  biceps  flexor  cruris. 

The  Third  Perforating  Artery  penetrates  the  Adductor  magnus 
somewhat  below  the  commencement  of  the  short  head  of  the  biceps, 
and  is  dispersed  upon  the  adductor  and  the  adjacent  portion  of  the 
flexor  muscles. 

24* 


11* 


CIRCULATORY  SYSTEM. 


The  Fourth  Perforating  Artery  penetrates  the  insertion  of  the  ad- 
ductor magnus  an  inch  and  a half  above  the  opening  in  it,  for  the 
femoral  artery;  it,  in  the  same  way,  supplies  the  posterior  face  of 
the  adductor  and  the  adjacent  muscles. 

As  a summary,  it  will  be  readily  understood  that  the  profunda  is, 
in  this  way,  through  the  external  and  the  internal  circumflex,  and 
through  the  perforating  arteries,  distributed  upon  all  the  large  mus- 
cles of  the  thigh. 

After  the  origin  of  the  profunda,  the  Femoral  Artery  gives  off,  at 
different  points  of  its  course- to  the  opening  of  the  adductor  magnus, 
several  twigs  the  size  of  a large  knitting  needle  ; which  go  to  the 
sartorius,  the  gracilis,  the  adductors  and  the  extensors  on  the  front 
of  the  thigh  ; but  they  are  too  inconstant  to  require  a more  particular 
description. 

The  Anastomosing  Artery  (. Arteria  Anastomotica ) is  the  last  branch 
of  the  femoral,  and  arises  just  before  it  perforates  the  adductor  mag- 
nus. It  descends  to  the  knee,  in  front  of  the  tendon  of  the  latter, 
concealed  by  the  internal  margin  of  the  vastus  internus  muscle.  It 
sends  off  many  small  twigs  to  the  adjacent  muscles,  and  terminates 
below  by  anastomosing  with  the  internal  articular  arteries.  It  is 
about  the  size  of  a crow-quill. 

The  Popliteal  Artery  {Arteria  Poplitcea)*  is  the  continuation  of  the 
femoral,  after  the  latter  has  passed  through  the  tendinous  insertion 
of  the  adductor  magnus;  and  extends  from  this  point  to  the  opening 
in  the  interosseous  ligament  of  the  leg,  just  below  the  head  of  the 
tibia.  It,  first  of  all,  passes  from  the  internal  margin  of  the  os  femo- 
ris,  to  the  notch  between  the  condyles ; being  there  placed  in  the 
middle  between  the  internal  and  the  external  hamstring  muscles, 
and  surrounded  by  a mass  of  adipose  matter  which  fills  up  the  hol- 
low of  the  ham.  It  is  in  contact,  anteriorly,  with  the  knee  joint,  and 
a little  below  the  latter  with  the  popliteus  muscle,  descending  there 
between  the  heads  of  the  gastrocnemius.  It  is  covered,  in  the  greater 
part  of  its  extent,  posteriorly,  by  the  popliteal  vein,  and  by  the  sci- 
atic nerve,  the  latter  being  more  superficial  than  the  vein. 

The  popliteal  artery  sends  off  some  small  branches  to  the  ham- 


* Anat.  Atlas,  Figs.  471,  473. 


POPLITEAL  ARTERY,  AND  ITS  BRANCHES. 


275 


string  muscles,  and  to  the  parts  contained  between  the  latter,  which 
are  too  irregular  and  inconstant  for  description.  The  following  arte- 
ries, also,  come  from  it: — 

1.  The  Superior  Internal  Articular  Artery  (Art.  Articularis  Supe- 
rior Interna)  arises  at  or  above  the  internal  condyle,  and  frequently 
consists  in  two  trunks.  It  passes  through  the  tendon  of  the  adductor 
magnus,  just  above  the  condyle ; it  then  begins  to  distribute  itself  in 
branches,  some  of  which  are  spent  upon  the  lower  part  of  the  vastus 
internus  muscle,  and  others  upon  the  superior  internal  part  of  the 
knee  joint. 

2.  The  Superior  External  Articulating  Artery  (Art.  Articularis 
Superior  Externa ) arises  from  the  popliteal,  somewhat  above  the 
external  condyle  of  the  os  femoris.  It  winds,  horizontally,  above 
the  external  condyle,  around  the  bone,  between  it  and  the  lower 
part  of  the  biceps  flexor  cruris,  and  is  then  distributed,  also,  in  two 
orders  of  branches,  some  of  which  supply  the  lower  part  of  the  vas- 
tus externus  muscle,  and  others  the  superior  external  portion  of  the 
knee  joint. 

3.  The  Middle  Articular  artery  (Art.  Articularis  Media)  is  smaller 
than  either  of  the  above,  and  sometimes  comes  from  one  of  them,  but 
generally  from  the  popliteal,  on  a line  with  the  articulation  of  the 
knee.  It  is  distributed  to  the  posterior  part  of  the  capsular  ligament, 
to  the  crucial  ligaments,  and  to  the  corresponding  adipose  matter. 

4.  The  Inferior  Internal  Articular  Artery  (Art.  Articularis  Inferior 
Interna)  arises  on  a line  with  the  inferior  part  of  the  internal  con- 
dyle, sometimes  lower  down.  Its  origin  is  very  much  concealed  by 
the  internal  head  of  the  gastrocnemius ; it  passes  beneath  the  latter, 
and  then  between  the  internal  lateral:  ligament  of  the  knee  and  the 
head  of  the  tibia;  consequently,  it  is  covered  by  the  internal  ham- 
string muscles.  It  afterwards  ascends  towards  tire  patella,  and  is 
distributed  in  numerous  branches  to  the  inferior  internal  part  of  the 
knee  joint,  and  to  the  adjacent  portion  of  the  tibia. 

5.  The  Inferior  External  Articular  Artery  (Art.  Articularis  Infe- 
rior Externa)  arises  near  the  last,  below  the  external  condyle,  being 
concealed  by  the  belly  of  the  plantaris.  It  passes,  horizontally,  or 
nearly  so,  between  the  popliteus  and  the  outer  head  of  the  gastroc-  • 


276 


CIRCULATORY  SYSTEM. 


nemius,  and  afterwards  beneath  the  tendon  of  the  biceps  and  the  ex- 
ternal lateral  ligament  of  the  joint,  around  the  external  face  of  the 
head  of  the  tibia.  It  gives  small  branches  to  these  several  parts,  and 
is  then  distributed,  by  two  orders  of  ramifications,  to  the  superficial 
and  to  the  more  deeply  seated  parts  at  the  external  inferior  portion 
of  the  knee  joint. 

These  several  articular  arteries  anastomose  - freely  with  each 
other,  and  are  minutely  ramified  on  the  knee  joint  and  the  contigu- 
ous structure.  They  also  anastomose  with  the  long  descending 
branch  of  the  external  circumflex  of  the  thigh,  with  the  anastomotica 
of  the  femoral,  and  with  the  tibial  recurrent. 

6.  The  Gastrocnemial  Arteries  ( Arteries  Gemellce)  are  two  in 
number,  one  for  each  head  of  the  gastrocnemius.  They  arise 
commonly  between  the  superior  and  the  inferior  articular  arteries, 
and  are  about  the  same  size.  They  penetrate  into  the  muscle,  and 
supply  it  with  blood,  terminating  their  course  near  the  lower  part  of 
its  bellies. 

Moreover,  some  small  branches,  which  go  to  the  contiguous  mus- 
cles, are  frequently  observed  here  ; also,  the  nutritious  artery  of  the 
tibia.  But  their  number  and  condition  are  very  inconstant.  Near 
tlie  head  of  the  fibula,  branches  go  from  the  popliteal  artery  to  the 
upper  end  of  the  soleus  muscle. 

Generally,  on  a level  with  the  aperture  in  the  upper  part  of  the 
interosseous  ligament,  but  sometimes  an  inch  or  two  higher  up,  the 
popliteal  artery  terminates  by  dividing  into  two  large  trunks,  the 
Anterior  and  the  Posterior  Tibial. 

The  Anterior  Tibial  Artery*  (Art.  Tibialis  Anterior ) passes  for- 
wards through  the  foramen  of  the  interosseous  ligament,  just  below 
the  head  of  the  fibula,  and  runs  down  the  front  of  the  leg  and  foot, 
as  far  as  the  base  of  the  metatarsal  bone  of  the  great  toe.  In  this 
course,  its  relative  situation  is  as  follows: 

It  rests  upon  the  front  of  the  interosseous  ligament  of  the  leg,  on 
a line  drawm  from  the  middle  anterior  part  of  the  head  of  the  fibula 
to  the  middle  of  the  ankle  joint.  Superiorly,  it  is  bounded  on  the 
tibial  side  by  the  tibialis  anticus  muscle,  and  on  the  other  by  the 
extensor  longus  digitorum : lower  down  on  the  leg,  the  place  of  the 


* Anat.  Atlas,  Fig.  474. 


ANTERIOR  TIBIAL  ARTERY,  AND  ITS  BRANCHES.  277 

latter  is  supplied  by  the  extensor  pollicis  pedis.  Somewhat  above 
the  ankle  joint  the  artery,  leaving  the  interosseous  ligament,  rests 
upon  the  front  of  the  tibia,  and  then  gets  to  the  top  of  the  foot,  be- 
tween the  joint  and  the  annular  ligament.  Under  the  ligament  it  is 
crossed  by  the  tendon  of  the  extensor  pollicis,  which  gets  to  its  in- 
ner side,  and  afterwards  continues  so.  The  anterior  tibial  nerve 
adheres  to  it,  in  its  whole  length. 

The  following  branches  come  from  the  anterior  tibial  artery : 

1.  The  Recurrent  Tibial  (Art.  Tibialis  Recurrens)  ascends  through 
the  upper  extremity  of  the  tibialis  anticus  muscle,  having  come  off 
from  the  anterior  tibial  immediately  upon  the  latter  getting  to  the 
front  of  the  leg.  Several  small  ramifications  pass  from  it  to  the 
heads  of  the  contiguous  muscles  on  the  tibia,  and  to  the  lower  part 
of  the  knee  joint,  where  it  anastomoses  with  the  lower  articular 
arteries  of  the  knee. 

2.  Several  small  arterial  twigs  are  afterwards  sent  to  the  mus- 
cles and  to  the  periosteum  of  the  leg,  as  the  anterior  tibial  descends ; 
but  they  are  too  inconstant  in  size  and  position  to  require  descrip- 
tion. 

3.  The  Internal  Malleolar  Artery  (Art.  Malleolaris  Interna ) arises 
from  the  anterior  tibial,  an  inch  or  two  above  the  ankle  joint.  It 
descends,  inwardly,  between  the  tibia  and  the  tendon  of  the 
tibialis  anticus,  and,  having  gained  the  internal  malleolus,  is  dis- 
tributed by  branches  upon  it  and  upon  the  adjacent  portion  of  the 
articulation. 

4.  The  external  Malleolar  Artery  (.Art.  Malleolaris  Externa ) con- 
sists most  commonly  in  two  arterial  twigs  of  small  size,  but  frequently 
in  one  only.  It  arises  in  front  of  the  ankle  joint,  and  going  out- 
wardly between  it  and  the  tendons  of  the  extensor  digitorum  longus, 
is  spent  upon  the  external  face  of  the  articulation,  where  it  inoscu- 
lates with  the  peroneal  artery. 

This  artery  is  sometimes  of  considerable  size,  in  which  case  it 
also  supplies  the  outer  part  of  the  tarsus,  and  is  a substitute  for  the 
next. 

5.  The  Tarsal  Artery  (Arteria  Tarsea')  arises  from  the  anterior 


278 


CIRCULATORY  SYSTEM. 


tibial,  somewhat  below  the  ankle  joint  near  the  scaphoides,  and, 
going  outwardly  beneath  the  extensor  brevis  digitorum  muscle,  it  is 
distributed  in  branches  near  the  external  ankle,  and  upon  the  outer 
upper  surface  of  the  tarsus.  It  anastomoses  with  the  external  mal- 
leolar, with  the  external  plantar,  and  with  the  metatarsal  artery. 

Some  small  branches  also  pass  from  the  anterior  tibial  at  this  point 
to  the  upper  internal  face  of  the  tarsus. 

6.  The  Metatarsal  Artery  [Art.  Metatarsea ) arisesjust  below  the 
last.  It  is  directed  forwards  and  outwards  beneath  the  extensor 
brevis  muscle,  and  forms  a sort  of  arch  at  the  roots  of  the  metatarsal 
bones.  It  furnishes  several  ramifications  to  the  upper  surface  of  the 
tarsus  and  the  contiguous  parts;  amongst  them  is  an  interosseal 
artery  for  each  of  the  three  outer  interosseal  spaces.  These  arteries 
communicate,  by  small  anastomoses,  with  the  arteries  of  the  sole  of 
the  foot,  both  at  the  bases  and  at  the  ends  of  the  metatarsal  bones, 
and  terminate  in  front  by  supplying  the  backs  of  the  small  toes. 

This  artery  is  sometimes  a branch  of  the  tarsal. 

7.  The  Dorsal  Artery  of  the  Great  Toe  [Art.  Dorsalis  Hallucis ) 
arises  from  the  anterior  tibial  at  the  root  of  the  first  metatarsal  bone. 
It  runs  along  the  superior  face  of  the  first  metatarsal  interval,  and 
having  reached  the  anterior  end  of  it,  divides  into  two  branches, 
one  of  which  goes  to  the  back  of  the  great  toe  and  the  other  to  the 
tibial  margin  of  the  next  toe. 

/ 

The  Anterior  Tibial,  in  its  course  from  the  ankle  joint  to  the  base 
of  the  first  metatarsal  bdne,  is  sometimes  called  Pedal  ( Arteria 
Pedicea;)  at  the  posterior  end  of  the  first  metatarsal  interval,  being 
still  of  considerable  size,  it  sinks  down  to  the  sole  of  the  foo|,  and 
joins  itself  to  the  external  plantar  artery  at  this  point. 

It  frequently  happens  (hat  the  anterior  tibial  being  small  in  its 
course  down  the  leg,  is  joined  by  the  continued  trunk  of  the  pero- 
neal, which  perforates  the  interosseous  ligament  somewhat  above 
the  ankle  joint.  Afterwards  the  trunk  formed  by  this  union,  being 
of  considerable  s'ze,  follows  the  course  and  has  the  distribution 
mentioned. 

The  Posterior  Tibial  Artery  ( Arteria  Tibialis  Posticu*)  is  some- 


* Anat.  Atlas,  Fig,  475. 


THE  POSTERIOR  TIBIAL  ARTERY. 


279 


times  called,  at  its  commencement,  till  it  gives  off  the  peroneal, 
tibio-peroneal;  it  extends  from  the  head  of  the  tibia  to  the  sinuosity 
of  the  os  calcis,  in  a line  from  the  middle  of  the  ham  to  the  internal 
ankle.  It  is  at  the  tibial  side  of  the  back  of  the  leg,  on  the  posterior 
face  of  the  flexor  longus  digitorutn  muscle;  and  covered  by  the 
fascia  of  the  latter.  In  the  two  superior  thirds  of  its  course,  it  is 
concealed  behind  by  the  gastrocnemius  and  the  solaeus  muscle:  in 
the  inferior  third,  it  is  at  the  internal  margin  of  the  tendo-achillis. 
At  the  ankle  joint,  before  it  passes  into  the  sinuosity  of  the  os  calcis, 
it  is  between  the  tendon  of  the  tibialis  posticus  and  that  of  the  flexor 
longus  pollicis  pedis,  being  covered  by  the  laciniated  ligament. 
It  is  accompanied,  at  its  external  margin,  by  the  posterior  tibial 
nerve. 

The  posterior  tibial  artery  is  distributed  after  the  following 
manner: 

1.  The  Peroneal  Artery  ( Arteria  Peronea ) is  its  first  branch  of  any 
importance,  and  is  but  little  smaller  than  the  continued  trunk.  It 
arises  an  inch  or  two  below  the  origin  of  the  anterior  tibial,  and 
extends,  on  the  posterior  face  of  the  leg,  to  the  external  ankle.  It 
is,  in  some  measure,  concealed  by  the  posterior  side  of  the  fibula, 
being  placed  there  between  the  origin  of  the  flexor  longus  pollicis 
muscle  and  the  external  edge  of  the  tibialis  posticus.  It  is  covered 
behind  by  the  flexor  longus  pollicis,  by  the  soleus,  and  by  the  gas- 
trocnemius; it  is,  therefore,  deep  and  of  extremely  difficult  access 
in  the  living  body. 

In  this  course,  it  sends  small  branches  to  the  gastrocnemius,  to 
the  soleus,  and  to  the  other  contiguous  muscles  on  the  back  of  the 
leg.  After  having  descended  two-thirds  of  the  length  of  the  fibula, 
it  divides  into  an  anterior  and  a posterior  branch.  The  former 
traverses  the  interosseous  ligament,  and  descending  in  front  of  it, 
covered  by  the  muscles  which  arise  from  the  lower  part  of  the 
fibula,  is  distributed  upon  the  upper  external  part  of  the  foot  near 
the  ankle  joint.  The  posterior  branch  continues  in  the  primitive 
course  of  the  peroneal  artery  at  the  internal  posterior  margin  of  the 
fibula,  and  descending  behind  the  tibio-peroneal  articulation, 
reaches  the  external  face  of  the  os  calcis:  it  detaches  several  small 
ramifications  to  the  contiguous  muscles;  and,  upon  the  os  calcis, 
is  divided  into  twigs  which  supply  the  adjacent  parts  and  the  integu* 
ments  below  the  external  ankle. 


2S0 


CIRCULATORY  SYSTEM. 


2.  In  the  descent  of  the  posterior  tibial  artery  to  the  hollow  of 
the  os  calcis,  it  detaches  several  small  muscular  branches,  princi* 
pally  to  the  tibialis  posticus,  and  to  the  flexors  of  the  toes.  One 
twig,  which  is  the  nutritious  artery  of  the  tibia,  comes  from  its 
upper  part  when  not  furnished  from  the  popliteal  artery,  and  enters 
the  foramen  on  the  posterior  surface  of  the  bone. 

While  the  posterior  tibial  is  in  the  hollow  of  the  os  calcis,  be- 
tween it  and  the  abductor  muscle  of  the  great  toe,  it  furnishes  some 
small  twigs  to  the  contiguous  muscles,  and  to  the  integuments  of 
the  sole  of  the  foot  ; it  then  divides  into  two  branches,  the  Internal 
and  the  External  Plantar  Artery.* 

The  Internal  Plantar  Artery  [Art.  Plantaris  Interna ) is  much 
smaller  than  the  other.  It  advances  between  the  abductor  pollicis 
pedis  and  the  internal  inferior  margin  of  the  bones  of  the  foot,  and 
terminates  at  the  anterior  end  of  the  first  metatarsal  bone,  by  join- 
ing the  internal  digital  artery  of  the  great  toe.  In  this  course,  it 
sends  continually,  small  ramifications  to  the  muscles  of  the  great  toe 
and  to  the  flexor  brevis  digitorum  pedis.  One  of  the  largest  of  these 
ramifications  comes  off  near  the  os  scaphoides,  and  cruises  along 
the  internal  margin  of  the  abductor  pollicis  to  its  anterior  end  ; 
another  becomes  superficial  on  the  sole  of  the  foot,  between  the  ab- 
ductor pollicis  and  the  flexor  brevis  digitorum,  and  goes  forward  as 
far  as  the  other. 

The  External  Plantar  Artery  [Art.  Plantaris  Externa ) is  the  con- 
tinuation of  the  posterior  tibial,  and  diverges  from  the  internal 
plantar  towards  the  outer  margin  of  the  sole  of  the  foot,  between  the 
flexor  brevis  digitorum  pedis  and  the  flexor  accessorius.  Having 
reached  the  internal  margin  of  the  abductor  minimi  digiti,  it  ad- 
vances along  the  latter  to  the  base  of  the  metatarsal  bone  of  the 
fourth  toe  ; it  then  makes  a curvature  forwards  and  inwards  across 
the  metatarsal  bones,  between  the  tendons  of  the  flexor  longus  digi- 
torum and  the  interosseous  muscles,  to  the  first  metatarsal  interval, 
where  it  is  joined  by  the  anterior  tibial  artery  from  above.  This 
curvature  is  the  Arcus  Plantaris,  of  which  the  concavity  is  behind 
and  inwards. 

The  external  plantar  artery  is  distributed  as  follows  : — 


Anat.  Atlas,  Figs.  476  to  479,  inclusive. 


POSTERIOR  TIBIAL  ARTERY,  AND  ITS  BRANCHES.  281 

Shortly  after  its  origin,  it  detaches  a branch  which  goes  backwards 
and  outwards,  and  which  keeping  close  to  the  os  calcis  in  front  of 
its  tuberosity,  is  distributed  to  the  heads  of  the  muscles  arising  from 
it,  and  to  the  outer  surface  of  the  heel ; it  also  sends  an  arteriole 
along  the  external  edge  of  the  abductor  minimi  digiti. 

At  the  base  of  the  fourth  metatarsal  bone  arises  a branch  called 
the  External  Digital  Artery  of  the  Little  Toe.  It  goes  at  first  deeply 
along  the  internal  margin  of  the  muscles  situated  on  the  fifth  meta- 
tarsal bone,  and,  afterwards,  at  the  head  of  the  latter,  it  gets  between 
them  and  the  bone,  and  is  distributed  along  the  external  margin  of 
the  little  toe. 

The  four  Digital  Arteries  of  the  foot  arise  next  successively  from 
the  arcus  plantaris,  at  or  near  the  metatarsal  intervals.  They  run 
along  the  inferior  surface  of  the  interosseous  muscles,  getting  to  the 
bases  of  the  first  phalanges  above  the  transversalis  pedis.  Each 
artery  there  bifurcates,  so  as  to  supply  the  opposed  surfaces  of  the 
adjacent  toes,  in  the  same  way  that  the  digital  arteries  of  the  hand  are 
distributed. 

The  digital  artery  of  the  first  metatarsal  interval  which  comes  from 
flie  internal  extremity  of  the  arcus  plantaris,  where  the  anterior 
tibial  artery  joins  the  latter,  goes  forwards  concealed  by  the  flexor 
brevis  of  the  great  toe:  just  behind  the  sesamoid  bones,  it  sends  a 
branch  which  supplies  the  internal  side  of  the  great  toe,  being  its  in- 
ternal digital  artery,  and  anastomoses  with  the  internal  plantar  artery. 
What  remains  of  it,  is  still  a trunk  of  considerable  magnitude,  which 
advancing  to  the  space  between  the  first  phalanx  of  the  great  toe 
and  of  the  toe  next  to  it,  there  bifurcates,  as  mentioned,  so  as  to 
supply  the  opposite  sides  of  these  two  toes. 

The  Perforating  Arteries,  as  they  are  called,  are  of  two  kinds,  the 
anterior  and  the  posterior.  The  former  arise  from  the  convexity  of 
the  plantar  arch  and  being  destined  principally  to  the  interosseous 
muscles,  anastomose  at  the  anterior  end  of  the  latter  with  the 
branches  from  the  metatarsal  artery,  which  supply  their  superior 
surface.  The  posterior  perforating  arteries  come  also  from  the 
plantar  arch,  and  penetrating  the  posterior  end  of  the  interosseous 
spaces,  anastomose  also  with  the  metatarsal  arteries  on  the  dorsum 
of  the  foot. 

The  preceding  trunks  of  the  internal  and  of  the  external  plantar 
Von.  II.—  25 


282 


CIRCULATORY  SYSTEM. 


arteries  are  the  principal  ones  which  are  found  in  the  bottom  of 
the  foot,  but  from  them  there  arise  an  immense  number  of  arte- 
rioles ; which,  descending  vertically  between  the  interstices  of  die 
muscles  and  of  the  aponeurosis  plantaris,  supply  the  adipose  matter 
and  the  skin  of  the  sole  of  the  foot,  so  as  to  render  them  extremely 
vascular. 


CHAPTER  III. 


Of  the  Veins. 

The  veins  of  the  body,  assembling  from  differing  points,  unite 
successively  into  the  ascending  and  into  the  descending  vena  cava, 
which  discharge  their  blood  into  the  right  auricle  of  the  heart.  The 
veins  of  the  head,  of  the  upper  extremities,  and  of  the  thorax,  run 
into  the  descending  cava,  while  the  veins  of  the  abdomen  and  of  the 
lower  extremities  concur  to  form  the  ascending  cava. 


SECT.  I. — OF  THE  VEINS  OF  THE  HEAD  AND  NECK.* 

Many  of  these  veins  are  described  elsewhere  with  the  encephalon 
and  with  the  eye,  to  wdiich  accounts  the  reader  is  referred.  The 
others  are  more  superficial,  and  arise  as  follows  : 

The  Facial  Vein  ( Vena  Facialis)  observes  the  course  of  the 
facial  artery,  being  placed  behind  the  latter.  It  arises  upon  the 
forehead  by  a considerable  number  of  roots,  which  unite  into  a 
single  trunk  called  the  frontal  vein.  This  vein  descends  from  the 
forehead,  over  the  root  of  the  nose,  along  the  internal  canthus  of 
the  orbit.  It  there  receives  re-enforcements  from  the  eyelids,  and 
anastomoses  with  the  ophthalmic  veins  ; descending  afterwards,  in 
the  same  vray  with  the  facial  artery,  and  taking  the  name  of  facial 
vein,  it  receives  successively  the  veins  from  the  nose,  from  the  outer 


Anat.  Atlas,  Figs.  480,  481,  482. 


OF  THE  VEINS. 


483 


side  of  the  orbicularis  palpebrarum,  from  the  upper  and  lower  lips, 
and  from  the  muscles  and  the  integuments  of  the  face.  It  descends 
to  the  neck  at  the  anterior  margin  of  the  masseter  muscle,  and  is 
then  augmented  by  the  ranine,  the  submental,  and  the  inferior  pala- 
tine veins,  and  immediately  afterwards  goes  into  the  internal  or  the 
external  jugular  vein. 

The  Ranine  Vein  ( Vena  Ranina ) arises  at  the  point  of  the  tongue, 
and  then  goes  along  its  under  surface,  where  it  can  be  readily  seen 
by  turning  up  the  end  of  the  tongue.  It  joins  the  facial  near  the 
posterior  margin  of  the  mylo-hyoideus  muscle. 

The  Submental  Vein  ( Vena  Submentalis ) arises  by  ramuscules  from 
the  sublingual  and  the  submaxillary  gland,  and  from  the  contiguous 
muscles.  It  joins  the  facial  vein  a little  below  the  last:  sometimes 
it  runs  into  the  superior  thyroidal  vein. 

The  Inferior  Palatine  Vein  ( Vena  Palatina  Inferior ) arises  princi- 
pally from  the  soft  palate  and  from  the  tonsil  gland,  but  receives 
a few  twigs  from  the  contiguous  parts.  It  corresponds  with  the  in- 
ferior palatine  artery,  a branch  of  the  dorsal  lingual,  (Dorsalis  Lin- 
gute  ;)  and  descends  the  pharynx  along  side  of  it,  and  terminates  in 
the  trunk  of  the  facial  near  the  last. 

The  Lingual  Vein  ( Vena  Lingualis ) has  its  origin  from  a plexus  of 
veins  situated  on  the  root  of  the  tongue  under  its  lining  membrane, 
between  the  epiglottis  and  the  foramen  caecum : branches  are  also 
sent  to  it  from  the  muscular  structure  of  the  tongue,  from  the  sublin- 
gual gland  and  from  the  adjacent  muscles,  and  it  anastomoses  with 
the  vena  ranina.  It  goes  backwards  between  the  hyoglossus  and 
the  mylo-hyoideus  muscle,  along  the  superior  margin  of  the  os 
hyoides,  and  then  discharges  into  the  internal  jugular  vein  near  the 
facial. 

The  Pharygeal  Vein  (Vena  Pliaryngea)  arises  from  a plexus  of 
veins  belonging  to  the  pharynx,  and  discharges  either  into  the  lingual 
or  into  the  internal  jugular  near  it. 

The  Superior  Thyroid  Vein  (Vena  Thyroidea  Superior ) corre- 
sponds with  the  distribution  of  the  superior  thyroid  artery,  in  the 


484 


CIRCULATORY  SYSTEM. 


origin  of  its  primitive  roots.  Having  collected  the  latter  into  one 
or  more  trunks,  it  passes  upwards  and  backwards  beneath  the 
sterno-hyoid  and  thyroid  muscles,  and  discharges  itself  into  the 
upper  part  of  the  internal  jugular,  or  into  one  of  the  large  branches 
of  the  external  jugular. 

The  Occipital  Vein  (Vena  Occipitalis)  arises  from  the  branches 
of  the  occipital  artery,  and  following  the  course  of  the  latter,  be- 
neath the  muscles  connected  with  the  mastoid  process  of  the  tem- 
poral bone,  it  is  discharged  into  the  upper  part  of  the  internal  jugu- 
lar or  of  the  external ; more  rarely  into  the  latter. 

The  Diploic  Veins  (Vence  Diploicce)  have  been  described  in  the 
account  of  the  bones  of  the  cranium  as  situated  between  the  two 
tables  in  the  diploic  structure,  and  commence  by  very  fine  capillary 
tubes  from  its  lining  membrane.  The  one  in  the  frontal  bone  dis- 
charges itself  into  the  frontal  vein,  that  in  the  occipital  bone  into  the 
occipital  vein,  and  the  two  in  the  parietal  bone  into  the  deep  tem- 
poral veins.  They  do  not  open  each  by  one  orifice,  but  by  several, 
which  make  their  terminations  not  very  distinct  or  abrupt : besides 
which,  they  communicate  freely  by  a crowd  of  ramuscules,  with  the 
veins  of  the  scalp  on  the  outside,  and  with  those  of  the  dura  mater 
internally. 

The  Superficial  Temporal  Vein  ( Vena  Temporalis  Superficialis ) 
corresponds  with  the  temporal  artery,  and  takes  its  rise  from  the 
terminating  ramifications  of  the  latter.  It  is  immediately  below  the 
skin.  Its  branches  communicate  freely  with  each  other,  and  with 
the  branches  of  the  frontal  and  of  the  occipital  vein:  at  the  zygoma 
it  receives  the  trunk  of  the  Middle  Temporal  Vein,  which,  collecting 
the  blood  from  the  temporal  muscle  and  other  parts  within  the 
zygoma,  perforates  the  temporal  fascia  to  discharge  itself  into  the 
superficial  temporal  vein. 

The  Temporal  Vein,  (Vena  Temporalis ,)  which  is  formed  by  the 
junction  of  the  Middle  and  the  Superficial  Temporal,  descends  over 
the  root  of  the  zygoma,  in  company  with  the  artery,  and  penetrates, 
like  the  latter,  through  the  substance  of  the  parotid  gland.  It  is 
joined,  near  the  neck  of  the  lower  jaw,  by  the  internal  maxillary 
vein.  It  is  also  joined,  in  its  descent  through  the  parotid  gland,  by 


VEINS  OF  THE  HEAD  AND  NECK. 


285 


the  anterior  auricular  veins,  by  the  parotid  veins,  and  by  the  trans- 
verse facial,  all  of  which  correspond  with  the  arteries  of  the  same 
name.  The  temporal  vein,  on  issuing  from  the  parotid  gland,  im- 
mediately afterwards  becomes  the  External  Jugular ; but,  occasion- 
ally, it  ends  wholly,  or  in  part,  in  the  Internal  Jugular. 

The  Internal  Maxillary  Vein  (Vena  Maxillaris  Interna)  is  derived 
from  the  terminating  ramifications  of  all  the  arteries  into  which 
the  internal  maxillary  is  divided;  it  is,  therefore,  composed  of  the 
spheno-palatine  vein,  which  brings  the  blood  from  the  nose,  of  the 
infra-orbital,  of  the  pterygoids,  inferior  maxillary,  deep-seated  tem- 
poral, and  so  forth,  with  the  exceptions  of  the  vein,  which  might 
belong  to  the  middle  artery  of  the  dura  mater,  but  which  does  not 
exist  according  to  Portal  and  to  Hippolytus  Cloquet.  By  the  aid 
of  the  spheno-palatine  vein,  the  internal  maxillary  communicates 
with  the  sinuses  in  the  bottom  of  the  cranium,  by  branches,  called 
the  Emissary  Veins  of  Santorini,*  which  pass  through  the  foramen 
ovale,  rotundum,  and  spinale.  It  also  communicates  with  the  plexus 
of  veins  on  the  side  of  the  pharynx. 

The  External  Jugular  Vein  (Vena  Jugularis  Externa)  is  generally 
the  continuation  of  the  temporal.  It  descends  on  the  neck  almost 
vertically,  between  the  platysma  myodes  and  the  sterno-mastoideus, 
in  the  direction  of  the  fibres  of  the  first,  and  crossing  those  of  the 
latter  obliquely.  Just  behind  the  clavicle,  at  the  external  margin  of 
the  sterno-mastoideus,  it  opens  into  the  subclavian  vein,  in  front  of 
the  scalenus  anticus  muscle.  Sometimes,  instead  of  one  trunk  only, 
there  are  two  or  three,  which  unite  at  a variable  distance  above  the 
subclavian.  This  vein  varies  also  in  its  size,  and  in  the  branches 
from  which  it  is  made  up  : sometimes  it  receives  the  facial  vein,  and 
on  other  occasions  the  latter  runs,  as  stated,  into  the  internal  jugular. 
The  condition  and  arrangement  of  the  internal  and  external  jugulars, 
are,  indeed,  so  inconstant,  in  regard  to  the  trunks  that  compose 
them,  that  it  is  scarcely  possible  to  give  more  than  a very  general 
description  of  them  with  tolerable  accuracy. 

The  external  jugular,  in  going  down  the  neck,  anastomoses  more 
or  less  with  the  internal  jugular,  either  directly  or  by  its  branches: 
one  of  these  anastomoses  is  found  near  the  angle  of  the  lower  jawg, 
about  the  trunk  of  the  facial  vein,  and  is  so  large  as  to  explain  the 

* Obs.  Anat.  chap.  iii.  p.  74. 

25* 


286 


CIRCULATORY  SYSTEM. 


difference  of  opinion  among  anatomists  in  regard  to  the  latter’s  ter- 
mination. Sometimes  the  occipital  vein,  or  a large  trunk  from  it, 
joins  the  external  jugular.  At  the  lower  part  of  the  neck,  the  ex- 
ternal jugular  is  augmented  by  the  superficial  cervical  veins.  Some 
of  these  come  from  the  lower  part  of  the  neck,  near  the  shoulder, 
and  join  the  jugular  just  above  the  clavicle  ; others  are  placed  on 
the  lower  front  part  of  the  neck,  above  the  sternum,  and  there  form 
with  each  other  a remarkable  and  an  irregular  plexus,  consisting  in 
numerous  meshes.  It  frequently  happens  that  the  external  jugulars 
of  the  two  sides,  just  before  they  terminate,  anastomose  with  each 
other  by  a large  horizontal  trunk,  which  runs  just  above  the  end  of 
the  sternum,  in  front  of  the  sterno-mastoid,  sterno-hyoid,  and  the 
sterno-thyroid  muscles : this  trunk,  on  other  occasions,  goes  more 
deeply,  and  behind  these  muscles,  from  one  subclavian  vein  to 
another,  or  to  a jugular;  its  mode  of  attachment  is,  indeed,  much 
varied:  when  it  exists,  however,  it  frequently  receives  several  of  the 
superficial  veins  of  the  neck,  and  the  inferior  thyroideal. 

The  Internal  Jugular  Vein  ( Vena  Jugularis  Interna ) extends 
from  the  basis  of  the  cranium  to  the  internal  margin  of  the  first  rib, 
at  the  insertion  of  the  .scalenus  anticus  muscle.  The  lateral  sinuses 
of  the  dura  mater,  receiving  ultimately  all  the  blood  of  the  brain,  of 
the  eye,  and  a portion  of  that  of  the  nose,  convey  it  from  the  cra- 
nium through  the  posterior  foramina  lac.era;  where  they  are  joined  to 
the  upper  end  of  the  internal  jugular  veins,  the  lining  membrane  of 
each  sinus  being  continuous  with  that  of  its  respective  vein.  Each 
vein  is  somewhat  enlarged  at  its  commencement,  which  is  therefore 
called  its  Gulf  or  Sinus  ; the  right  vein  is  frequently  larger  than  the 
left.  The  internal  jugular  then  descends  in  front  of  the  transverse 
processes  of  the  vertebra  of  the  neck,  on  the  outer  side  of  the  inter- 
nal and  of  the  primitive  carotid  artery,  and  of  the  pneumogastric 
nerve.  It  is  concealed  above  by  the  styloid  process  of  the  temporal 
bone,  and  the  muscles  belonging  to  it ; it  is  crossed  half  way  down 
the  neck,  by  the  omo-hyoideus  muscle  ; and,  in  the  greater  part  of 
its  course,  is  beneath,  and  nearly  parallel  with  the  anterior  edge  of 
the  sterno-mastoideus.  Having  got  behind  the  sternal  end  of  the  cla- 
vicle, it  is  joined  at  the  internal  edge  of  the  scalenus  anticus  by  the 
subclavian  vein,  and  the  union  of  the  two  forms  the  vena  inno- 
minata. 

The  internal  jugular  receives  frequently  the  large  anastomotic 


VEINS  OF  THE  HEAD  AND  NECK. 


287 


branch,  just  alluded  to,  from  the  external  jugular,  at  the  under  mar- 
gin of  the  parotid  gland,  between  the  digastric  muscle  and  the 
lower  jaw,  and  it  is  in  this  vicinage  that  it  is  generally  re-enforced 
by  the  Occipital;  the  Lingual;  the  Facial;  the  Pharyngeal;  and 
the  Superior  Thyroidal  Veins,  that  have  been  described. 

The  Vena  Innominata,  or  Brachio  Cephalic  Vein  is  the  trunk 
formed  on  either  side  by  the  junction  of  the  subclavian  with  the 
internal  jugular.  On  the  right  side  it  looks  like  the  continuation  of 
the  internal  jugular,  and  descends  in  contact  with  the  right  pleura, 
behind  the  right  side  of  the  sternum,  for  the  distance  of  an  inch  or 
thereabouts.  On  the  left  side  it  crosses  behind  the  superior  end  of 
the  sternum,  descending  obliquely  in  this  course,  from  left  to  right, 
until  it  joins  the  trunk  on  the  right  side.  It  lies  in  front  of  the  great 
vessels  proceeding  from  the  arch  of  the  aorta ; and  is  much  longer 
than  the  trunk  of  the  other  side.  A common  name  for  it  is  the 
Transverse  Vein. 

The  Vena  Cava  Superior,  or  Descendens,  arises  from  the  junction 
of  the  two  vense  innominatse.  It  begins  between  the  cartilage  of  the 
first  rib  on  the  right  side,  and  the  arch  of  the  aorta,  and  descends  to 
the  superior  posterior  part  of  the  right  auricle,  into  which  it  empties 
itself.  Its  course  is  not  entirely  vertical,  but  inclining  somewhat  to 
the  left  side  and  forward.  It  is  about  three  inches  long.  The  supe- 
rior third  of  it  is  free,  and  is  in  contact  on  the  right  with  the  pleura, 
and  on  the  left  with  the  arteria  innominata  ; the  remaining  portion 
of  it  is  invested  by  the  pericardium,  and  has  the  aorta  on  its  left  an- 
terior face.'* 

The  following  venous  trunks  discharge  into  the  vense  innominatse, 
or  into  the  descending  cava.  The  Inferior  Thyroidal;  the  Verte- 
bral ; the  Superior  Intercostal ; the  Internal  Mammary ; the  Vena 
Azygos,  and  some  others  of  smaller  size. 

1.  The  Inferior  Thyroid  Vein  ( Vena  Thyroidea  Inferior ) arises 
from  the  inferior  part  of  the  thyroid  gland,  by  many  small  roots, 
which  anastomose  with  those  of  the  opposite  side.  It  descends  in 
front  of  the  trachea,  involved  in  the  loose  cellular  and  fatty  matter 

* In  some  very  rare  cases  there  have  been  two  descending  venas  cavae,  one 
for  the  right  side  and  the  other  for  the  left.  J.  F.  Meckel. 


288 


CIRCULATORY  SYSTEM. 


lying  upon  it,  and  empties  itself  into  the  left  brachio-cephalic  vein, 
or  Transverse  Vein. 

There  is  occasionally  another  thyroid  vein,  called  the  middle, 
which  discharges  itself  into  the  lower  part  of  the  internal  jugular. 

2.  The  Vertebral  Vein  ( Vena  Vertebralis ) is  placed  in  the  same 
canal  with  the  vertebral  artery.  At  its  upper  extremity  it  anasto- 
moses with  the  occipital  sinus,  by  a branch  lodged  in  the  posterior 
condyloid  foramen.  In  its  descent  of  the  canal  of  the  transverse 
processes,  it  communicates  at  each  intervertebral  foramen  with  the 
vertebral  sinuses,  and  also  receives  a branch  from  the  muscles  of 
the  neck.  It  issues  at  the  sixth  transverse  process,  and  going  on 
the  right  side  behind  the  subclavian  artery,  but  on  the  left,  in  front 
of  it,  is  finally  emptied  into  the  commencement  of  the  vena  in- 
nominata. 

3.  The  Superior  Intercostal  Vein  ( Vena  Intercostalis  Superior)  is 
on  the  right  side  an  inconsiderable  trunk,  sometimes  deficient, 
which  commences  by  branches  belonging  to  the  first  two  intercos- 
tal spaces,  and  empties  into  the  vena  innominata  just  below  the 
vertebral.  On  the  left  side  it  is  much  larger,  and  arises  from  the 
six  or  eight  superior  intercostal  spaces.  It  lies  on  the  left  side  of 
the  bodies  of  the  upper  dorsal  vertebrae,  and  at  each  intercostal 
space,  as  it  ascends,  receives  its  contribution  of  an  intercostal  vein, 
corresponding  with  the  intercostal  artery  ; it  also  receives  branches 
from  the  oesophagus,  and  about  the  third  dorsal  vertebra  the  left 
bronchial  vein  is  discharged  into  it.  Issuing  from  the  thorax  above, 
it  discharges  into  the  left  vena  innominata  near  its  commence- 
ment. 

4.  The  Internal  Mammary  Vein.  ( Vena  Mammaria  Interna ) 
arises  from  the  terminating  branches  of  the  internal  mammary  ar- 
tery, and  in  its  situation  and  course  corresponds  with  the  latter.  It 
is  re-enforced  by  small  branches  from  the  diaphragm,  the  pericar- 
dium, and  the  thymus  gland.  Each  internal  mammary  vein  dis- 
charges itself  on  its  respective  side  into  the  vena  innominata  near 
the  superior  intercostal. 

5.  The  Vena  Azygos*  is  placed  in  the  posterior  mediastinum. 


* Anat.  Atlas,  Figs.  489,  490. 


VEINS  OF  THE  HEAD  AND  NECK. 


289 


on  the  right  anterior  margin  of  the  Dorsal  Vertebrae,  and  dis- 
charges itself  in  making  an  arch  forwards  over  the  root  of  the 
right  lung,  into  the  descending  cava,  just  above  the  introduction  of 
the  latter  into  the  pericardium.  Its  orifice  there  is  supplied  with  a 
membranous  duplicature  or  valve,  which  prevents  the  blood  once 
discharged  from  re-entering  it.  The  valve  is  sometimes  double, 
and  also  somewhat  removed  from  the  orifice.  It  was  the  observa- 
tions of  these  valves,  first  of  all,  which  called  the  attention  of  Syl- 
vius and  of  Charles  Etienne  to  their  existence  in  other  veins. 

This  vein  begins  in  the  abdomen,  either  by  an  anastomosis  with 
the  ascending  cava,  or  with  the  upper  lumbar  vein  ; it  then  ascends 
into  the  thorax  through  the  aortic  orifice  of  the  diaphragm,  and 
continuing  to  mount  upwards  beneath  the  pleura  it  lies  on  the  right 
side  of  the  thoracic  duct,  and  crosses  in  front  of  the  intercostal 
arteries  of  the  right  side.  In  this  course,  it  receives  from  the  ten 
inferior  intercostal  spaces  of  the  right  side,  their  respective  inter- 
costal veins  corresponding  in  their  origin  and  course  with  the  in- 
tercostal arteries.  About  the  sixth  vertebra  of  the  back,  it  receives 
a trunk  ( Vena  Hemiazygos)  which  is  formed  from  the  four  or  six 
lower  intercostal  veins  of  the  left  side,  and  commences  in  the  ab- 
domen, also  by  anastomosis  with  the  left  emulgent  vein  or  the  left 
superior  lumbar,  and  which  gets  into  the  thorax  either  through  the 
aortic  orifice  of  the  diaphragm,  or  through  a special  opening  to 
the  left  of  it.  The  vena  azygos  also  receives  some  small  ramifica- 
tions from  the  oesophagus,  and  near  the  fourth  dorsal  vertebra,  the 
right  bronchial  vein  is  discharged  into  it.  Other  small  ramifica- 
tions join  it  from  the  parietes  of  the  descending  cava,  of  the  aorta, 
and  of  the  right  pulmonary  artery.  Branches  also  proceed  to  it, 
or  to  the  intercostal  veins  from  the  interior  of  the  vertebral  canal 
at  each  intervertebral  foramen. 

This  vein  is  commonly  spoken  of  by  anatomists,  as  forming  a 
great  anastomosis  between  the  ascending  and  the  descending  cava. 
The  tendency  to  establish  this  anastomosis  is  strikingly  confirmed 
by  a preparation  made  by  myself,  when  I was  a student  in  this 
institution  in  1813  ; and  now  in  the  Anatomical  Cabinet.  In  it  the 
ascending  cava,  instead  of  emptying,  as  usual,  into  the  lower  part 
of  the  right  auricle,  ascends  on  the  right  side  of  the  dorsal  verte- 
brae, and  supplanting  in  situation  and  office  the  vena  azygos,  dis- 
charge itself  into  the  descending  cava,  in  a manner  corresponding 


290 


CIRCULATORY  SYSTEM. 


with  the  vena  azygos,  by  making  a curvature  forwards  over  the 
root  of  the  right  lung. 

The  Sinuses  of  the  Vertebral  Column*  ( Sinus  Columnce  Verte- 
bralis ) are  situated  in  the  vertebral  cavity,  on  the  posterior  face  of 
the  bodies  of  the  vertebrae,  and  in  front  of  the  dura  mater  of  the 
spinal  marrow.  They  are  two  long  veins,  one  at  each  margin  of 
the  posterior  vertebral  ligament,  and  extend  from  the  foramen  mag- 
num occipitis  to  the  inferior  end  of  the  sacrum.  They  are  main- 
tained in  their  places  by  a loose  cellular  tissue  between  the  bones 
and  the  dura  mater,  and  therefore,  unlike  the  sinuses  of  the  brain, 
are  entirely  independent  of  the  dura  mater. 

These  sinuses  are  small  where  they  begin  in  the  sacrum,  and  are 
there  merely  two  cylindrical  veins  surrounded  by  a loose  cellular  sub- 
stance, and  which  have  an  anastomosis  between  them.  In  ascend- 
ing the  spine  they  enlarge,  but  not  continually,  as  they  are  some- 
what smaller  in  the  cervical  than  in  the  dorsal  vertebra.  On  the 
body  of  each  vertebra  they  are  rather  larger  than  on  the  interverte- 
bral substance  : this  gives  them  a knotted  appearance,  which  is  es- 
pecially distinct  in  the  loins. 

At  the  middle  of  each  vertebra  they  are  joined  to  one  another  by 
transverse  branches,  which  pass  beneath  the  posterior  vertebral  liga- 
ment, and  receive  the  veins  belonging  to  the  cellular  structure  of 
the  bone.  Externally,  they  communicate  with  the  vertebral  veins 
in  the  transverse  processes  of  the  neck,  with  the  intercostal,  and 
with  the  lumbar  veins,  as  an  opening  occurs  between  the  adjacent 
vertebra.  They  also  receive  many  delicate  veins  from  the  dura 
mater  of  the  spine.  These  two  trunks  terminate  at  their  upper  end 
by  an  anastomosis,  through  the  anterior  condyloid  foramen,  with  the 
internal  jugular  : they  also  terminate  by  anastomosis  with  the  ante- 
rior occipital  sinus  and  with  the  vertebral  veins. 

From  the  arrangement  of  these  sinuses,  it  appears  that  each  bone 
of  the  spine  has  its  own  venous  system  or  circle  ; which  also  is  the 
case  in  regard  to  the  corresponding  section  of  medulla  spinalis  in 
early  life,  when  it  occupies  the  whole  length  of  the  spine.  Each 
of  these  circles,  by  the  freedom  of  their  anastomoses,  therefore,  forms 
a link  in  a long  chain  of  venous  circles  belonging  to  the  structure  of 
the  spine. 

* G.  Bresehet,  Essai  sur  les  Veines  du  rachis.  Paris,  1819.  Anat.  Atlas, 
Figs.  483,  484,  485. 


VEINS  OF  THE  UPPER  EXTREMITIES. 


291 


SECT.  II. — OF  THE  VEINS  OF  THE  UPPER  EXTREMITIES.* 

The  veins  of  the  upper  extremities  are  superficial  and  deep-seated, 
and  arise  from  the  distribution  of  the  arteries. 

The  Deep-seated  Veins  are  found  in  company  with  each  arterial 
ramification,  there  being  two  veins  to  one  artery  generally.  We 
thus  have  them  observing  the  course  of  the  arteries  of  the  hand,  of 
the  fore-arm,  of  the  arm,  and  of  the  shoulder.  At  the  bend  of  the 
arm,  the  two  radial  and  the  two  ulnar  veins  coalesce  into  the  two 
brachial  veins,  which  attend  the  brachial  artery,  one  on  each  of  its 
sides,  and  at  intervals  throw  anastomotic  branches  across  it.  Some- 
times, but  one  of  these  trunks  exists,  with  the  exception  of  the 
lower  part  of  the  arm,  where  there  are  most  commonly  two.  The 
trunk  (or  trunks,  as  the  case  may  be,)  is  joined  by  the  basilic 
vein,  at  a point  varying  from  the  middle  of  the  arm  to  the  axilla. 
These  venae  comites,  or  satellites,  are  invariably  called  after  the 
arteries  which  they  attend,  and  having  no  difference  from  the 
latter  in  relative  situation,  a farther  description  of  them  may  be  dis- 
pensed with. 

The  Superficial  Veins  lie  between  the  skin  and  the  brachial  apo- 
neurosis, and  are  considerably  larger  than  the  preceding.  Their 
earliest  roots  are  seen  on  the  back  of  the  fingers ; they  then  appear 
on  the  back  of  the  hand,  on  the  posterior  of  the  lower  end  of  each 
interosseous  space.  There  are  commonly  six  trunks  in  all : the  one 
on  the  ulnar  side  of  the  hand  and  the  three  next  to  it,  converge  to- 
wards the  middle  of  the  back  of  the  carpus  into  a single  trunk;  the 
two  others,  one  of  which  comes  from  the  thumb  and  the  other  from 
the  back  of  the  fore-finger,  converge  to  the  outer  end  of  the  carpus, 
and  there  form  a single  trunk  also.  Between  these  several  trunks, 
there  are  frequent  anastomoses,  and  they,  finally,  assemble  into  two 
principal  branches  called  the  Cephalic  and  the  Basilic  Vein. 

The  Cephalic  Vein  (Vena  Cephalica , Radialis  Cutanea ) is  the 
trunk  which  comes  from  the  thumb  and  from  the  fore-finger,  and 
has  at  first  the  name  of  Cephalica  Pollicis.  It  ranges  along  the  an- 
terior and  radial  margin  of  the  fore-arm,  and  receives,  continually, 


* Anat,  Atlas,  Figs.  486,  487,  488,  494. 


292 


CIRCULATORY  SYSTEM 


an  augmentation  from  small  collateral  branches  on  the  back  of  the 
fore-arm.  Having  reached  the  bend  of  the  arm,  it  then  ascends  along 
the  external  margin  of  the  biceps  flexor  cubiti  till  it  touches  the  lower 
margin  of  the  pectoralis  major  muscle  ; it  then  rises  superficially  along 
the  interstice  between  this  muscle  and  the  deltoid,  to  within  eight  or 
ten  lines  of  the  clavicle,  where  it  dips  down  to  join  the  axillary 
vein.  Along  the  arm,  it  receives  some  small  secondary  cutaneous 
branches. 

The  Basilic  Vein  ( Vena  Basilica , Cubitalis  Cutanea ) is  larger  than 
the  cephalic,  and  begins  by  the  trunk  which  comes  from  tire  ulnar 
side  of  the  back  of  the  hand,  and  is  first  called  the  Vena  Salvatella. 
On  the  fore-arm,  the  basilic  frequently  consists  in  two  long  trunks, 
the  anterior  and  the  posterior ; in  this  case  the  posterior  is  the  prin- 
cipal one,  and  runs  along  the  internal  posterior  edge  of  the  ulna, 
until  it  comes  to  the  bend  of  the  arm ; it  then  mounts  over  the  latter, 
rising  obliquely  in  front  of  the  internal  condyle.  The  anterior 
branch  begins  near  the  palm  of  the  hand,  runs  up  in  front  of  the 
ulnar  side  of  the  fore-arm,  and  discharges  itself  into  the  median 
basilic  vein  over  the  brachial  artery  in  front  of  the  bend  of  the  arm. 
These  two  trunks,  or  one  as  the  case  may  be,  receive  the  cutaneous 
veins  belonging  to  the  ulnar  side  of  the  fore-arm. 

Above  the  elbow  joint,  the  basilic  gets  below  the  fascia  of  the 
arm  at  the  inner  edge  of  the  biceps,  and  about  the  middle  of  the 
arm  becomes,  by  its  junction  with  the  venrn  satellites,  the  Brachial 
Vein;  but  sometimes,  as  mentioned,  this  junction  occurs  much 
higher  up. 

The  Median  Vein  '{Vena  Mediana ) arises,  by  branches,  from  the 
-wrist,  from  the  palm  of  the  hand,  and  from  the  middle  of  the  front 
of  the  fore-arm.  It  forms  a trunk  which  ascends  in  front  of  the 
fore-arm,  and  which  a few  inches  below  the  bend  of  the  arm,  di- 
vides into  two.  One  branch  runs  outwardly,  in  ascending  for  an 
inch  or  two,  and  joins  at  the  outer  side  of  the  bend  of  the  arm,  the 
cephalic  vein ; it  is  called,  therefore,  the  Median  Cephalic.  The 
other  branch  continues  to  ascend,  and,  crossing  obliquely  the  di- 
rection of  the  brachial  artery,  it  receives,  near  the  latter,  the  an- 
terior trunk  of  the  basilic  vein,  and  somewhat  above  the  bend  of 
the  arm,  runs  into  the  proper  basilic  vein  : it  is  called  the  Median 
Basilic. 


VEINS  OF  THE  UPPER  EXTREMITIES. 


293 


There  is  frequently  a departure  from  the  preceding  arrangement 
of  the  median  vein ; the  most  common  is  where  a trunk  begins 
from  the  cephalic  below  the  bend  of  the  arm,  and  runs  obliquely 
in  front  of  the  latter  to  join  the  main  trunk  of  the  basilic  above  the 
elbow  joint.  This  oblique  trunk  stands  in  the  place  of  median 
cephalic  and  median  basilic,  and  receives  successively  the  median, 
the  anterior  and  the  posterior  basilic.  It  is  frequently  the  median 
itself,  and  has  a short  anastomosis,  in  such  case,  with  the  cephalic 
vein. 

The  Superficial  Veins  anastomose  frequently  with  each  other, 
so  that,  when  they  are  all  fully  injected,  a plexus  of  veins  is  found 
immediately  beneath  the  skin  of  the  upper  extremity  from  one  end 
to  the  other.  The  Venae  Satellites  also  anastomose  frequently  by 
branches  which  cross  the  artery  to  which  they  belong.  At  the 
bend  of  the  arm,  at  the  wrist,  and  in  different  places,  there  are  ' 
also  anastomoses  between  the  deep-seated  and  the  superficial 
veins. 

The  Axillary  Vein  ( Vena  Axillaris ) results  from  the  union  of  the 
basilic  with  the  brachial  vein.  It  is  below  and  in  front  of  the  axil- 
lary artery,  being  included  in  the  same  sheath  with  it,  and  also  in- 
volved with  the  axillary  plexus  of  nerves.  It  retains  its  name  from 
the  lower  margin  of  the  arm-pit  to  the  under  surface  of  the  clavicle, 
where,  like  the  artery,  it  is  then  called  subclavian.  In  this  course 
it  is  joined  near  the  points  where  the  corresponding  arteries  are 
given  off,  by  the  Anterior  and  the  Posterior  Circumflex  Vein ; by 
the  Scapular  ; and  by  the  External  Thoracics. 

The  Subclavian  Vein  ( Vena  Subclavia ) extends  from  the  termina- 
tion of  the  axillary  to  the  vena  innominata,  where  the  latter  is  con- 
stituted by  the  junction  of  the  internal  jugular  with  the  subclavian. 

In  its  course  it  goes  under  the  subclavian  muscle,  and  is  in  front  of 
the  subclavian  artery  from  the  beginning,  but  near  it : afterwards 
it  is  separated  from  the  artery  by  the  latter  going  between  the  an- 
terior and  the  middle  scalenus  muscle  ; whereas  the  vein  runs  over 
the  anterior  end  of  the  first  rib,  in  front  of  the  insertion  of  the 
scalenus  anticus. 

The  Subclavian  Vein  is  joined  by  some  branches  coming  from 
the  shoulder  and  from  the  lower  part  of  the  neck ; and,  at  the 

Vol.  II.— 26 


294 


CIRCULATORY  SYSTEM. 


outer  margin  of  the  origin  of  the  sterno-mastoid  muscle,  it  is  aug- 
mented by  the  addition  to  it  of  the  external  jugular.  It  terminates 
at  the  internal  margin  of  the  scalenus  anticus,  as  mentioned  in  the 
vena  innominata. 


SECT.  III. — VEINS  OF  THE  LOWER  EXTREMITIES.* 

The  veins  of  the  lower  extremities,  like  those  of  the  upper,  are 
deep-sealed  and  superficial.  The  former  follow  the  course  of  the 
arteries,  and  are  the  venre  satellites;  there  being,  for  the  most  part, 
two  veins  for  every  artery  as  far  up  as  the  ham,  and  also  as  re- 
gards the  muscular  branches  of  the  thigh.  These  veme  satellites 
adhere  closely  to  the  artery,  and  are  separated  from  each  other  by 
the  latter.  They  also  have  frequent  anastomoses  with  each  other 
across  the  artery. 

The  Popliteal  Vein  ( Vena  Poplitea)  is  a single  trunk  formed  by 
the  union  of  the  anterior  tibial,  the  posterior  tibial,  and  the  peroneal 
vein.  It  begins  on  the  posterior  part  of  the  head  of  the  tibia,  and 
extends  upwards  through  the  ham  to  the  perforation  in  the  adductor 
magnus  muscle,  which  transmits  the  femoral  artery.  It  is  situated 
on  the  posterior  face  of  the  popliteal  artery,  to  which  it  closely 
adheres;  and  behind  it  is  the  popliteal  nerve,  the  continuation  of 
the  great  sciatic. 

The  Femoral  Vein  ( Vena  Femoralis ) is  the  continuation  upwards 
of  the  popliteal:  it  at  first  is  placed  behind. the  artery,  but  in  a short 
space  it  gets  to  its  interior  face,  and  continues  to  adhere  to  it,  in 
that  situation,  up  to  Poupart’s  ligament,  where  it  becomes  the  ex- 
ternal iliac  vein.  At  the  usual  distance  below  the  groin,  where  the 
arteria  profunda  is  given  off’,  the  femoral  vein  receives  the  vena 
cruralis  profunda,  which  is  derived  from  the  branches  of  this  artery, 
and  is  rather  more  superficial  than  it;  the  two,  however,  adhere 
closely  together.  Just  below  Poupart’s  ligament  the  femoral  vein 
receives  several  small  branches  of  veins  corresponding  with  the  ex- 
ternal pudic  arteries. 


* Anat.  Atlas,  Figs.  493  to  497,  inclusive. 


VEINS  OF  THE  LOWER  EXTREMITIES. 


295 


The  Small  Saphena  ( Vena  Saphena  Minor  Externa ) commences 
by  several  small  branches  near  the  external  side  of  the  top  of  the 
foot,  and  the  external  ankle  ; a trunk  is  formed  by  them  behind  the 
latter,  which  ascends  along  the  tendo-achillis  and  the  posterior  face 
of  the  gastrocnemius  muscle,  collecting  several  small  veins  from  the 
back  of  the  leg  in  its  course.  This  vein  is  superficial  in  its  whole 
length,  being  placed  immediately  beneath  the  skin.  In  the  ham,  it  goes 
for  a short  distance  along  the  internal  face  of  the  popliteal  nerve, 
and  then  makes  a dip  through  the  adipose  matter  there  to  empty 
into  the  popliteal  vein. 

It  is  said,  by  Portal,  that  the  branches  of  this  vein  become  very 
apparent  in  persons  who  suffer  from  podagra,  and  from  enlarge- 
ment of  the  lymphatic  glands  in  the  ham.  In  such  case,  their 
distention  has  been  relieved  by  the  application  of  leeches  along 
them. 

The  Great  Saphena  ( Vena  Saphena  Magna , Interna ) is  also  super- 
ficial, has  its  primitive  roots  coming  from  the  internal  upper  part  of 
die  foot,  and  from  the  sole  of  the  latter.  These  branches  are  as- 
sembled into  a trunk  which  passes  upwards  in  front  of  the  internal 
ankle,  then  ascends  along  the  internal  face  of  the  leg,  in  a line  cor- 
responding with  the  posterior  margin  of  the  tibia.  The  great 
saphena  continues  its  ascent  over  the  internal  condyle  near  its  posterior 
part,  and  then  mounts  up  the  internal  face  of  the  thigh,  in  aline  cor- 
responding nearly  with  the  internal  margin  of  the  sartorius  muscle. 
It  finally  terminates  in  the  femoral  vein,  about  twelve  or  eighteen 
lines  below  Poupart’s  ligament,  an  opening  being  left  in  the  fascia 
femoris  for  this  purpose. 

In  the  whole  of  this  course  the  great  saphena  is  situated  between 
the  skin  and  the  fascia  of  the  lower  extremity ; it  is,  consequently, 
so  superficial,  that  in  persons  of  moderate  corpulency  it  is  very 
visible,  and  by  slight  pressure  above,  along  with  the  erect  position, 
it  becomes  so  much  swollen,  that  it  is  easily  opened  Avith  the  lancet 
where  it  passes  OA'er  the  internal  ankle.  It  receives,  in  its  ascent, 
small  branches  from  the  anterior  and  posterior  part  of  the  leg,  from 
the  corresponding  surfaces  of  the  thigh,  and  near  its  termination  it 
gets  a few  of  the  external  pudendal  veins. 

When  the  great  and  the  small  saphena  veins  are  successfully  in- 
jected, their  branches  are  seen  to  form  a considerable  number  of 


296 


CIRCULATORY  SYSTEM. 


anastomoses,  which  thereby  produce  a remarkable  venous  net-work, 
just  beneath  the  skin  of  the  whole  inferior  extremity. 


SECT.  IV. — VEINS  OF  THE  ABDOMEN.* 

The  External  Iliac  Vein,  ( Vena  lliaca  Externa ,)  being  the  con- 
tinuation of  the  femoral  vein,  passes  into  the  abdomen,  under  Pou- 
part’s  ligament,  and  in  contact  with  the  internal  margin  of  the  ex- 
ternal iliac  artery.  It  there  receives  the  epigastric,  and  the  circum- 
flex iliac  veins,  corresponding  with  the  arteries  of  the  same  name ; 
it  also  receives  a vein  of  some  size,  which  enters  by  the  abdominal 
canal  in  adhering  to  the  spermatic  chord,  and  which  comes  from  the 
coats  of  the  testicle. f It  keeps  then  along  the  internal  side  of  the 
artery,  somewhat  behind  it,  at  the  superior  margin  of  the  pelvis,  and 
joins  the  hypogastric  vein  opposite  to  the  sacro-iliac  junction,  and 
thereby  forms  the  common  iliac  vein. 

The  Hypogastric  Vein  [Vena  Hypogastrica,  lliaca  Interna ,)  comes 
from  the  inferior  part  of  the  pelvis  in  front  of  the  sacro-iliac  junction, 
and  in  company  with  the  hypogastric  artery.  It  arises  by  branches 
corresponding  with  the  distribution  of  the  latter  to  the  viscera  of  the 
pelvis,  and  to  its  external  parts ; these  branches  are  so  numerous  at 
particular  points,  and  have  such  frequent  anastomoses,  that  they  are 
formed  into  a Plexus.  Thus,  there  is  a hemorrhoidal  plexus  for  the 
lower  part  of  the  rectum,  a vesical  for  the  bladder,  a sacral  for  the 
sacrum,  a pudendal  for  the  parts  of  generation  in  the  male,  a vaginal 
for  the  vagina,  and  an  uterine  for  the  uterus  of  the  female. 

The  Plexus  Plemorrhoidalis,  besides  being  connected  with  the 
hypogastric,  also  anastomoses  with  the  branches  of  the  vena  por- 
tarum. 

The  Plexus  Vesiealis  is  different  in  the  two  sexes.  In  man  it 
commences  at  the  extremity  of  the  penis  by  several  branches,  which 
unite  into  two  trunks  of  considerable  size,  the  Venae  Dorsales  Penis.j: 
The  latter  go  along  the  upper  face  of  the  penis,  near  or  at  its  middle, 

* Anat.  Atlas,  Figs.  489  to  492,  inclusive. 

f H.  Cloquet,  Traite  D’Anat. 

\ They  are  frequently  found  to  unite  into  a single  trunk,  called,  in  such  case, 
the  Vena  Magna  Ipsius  Penis. 


VEINS  OF  THE  ABDOMEN. 


29? 


to  the  symphysis  of  the  pubesj  continually  receiving  in  this  course 
small  trunks  from  the  integuments  of  the  penis  and  from  the  scrotum. 
They  then  get  into  the  pelvis  between  the  root  of  the  penis  and  the 
symphysis  pubis,  and  continue  horizontally  backwards  on  the  side 
of  the  prostate  gland,  of  the  vesiculae  seminales,  and  of  the  lower 
fundus  of  the  bladder.  They  receive  many  branches  from  these 
parts,  which,  with  the  frequency  of  the  anastomoses  about  here,  con- 
stitute the  vesical  plexus.  The  latter,  finally,  discharges  into  the 
lower  part  of  the  hypogastric  vein  by  two  or  more  branches. 

In  the  female  the  vesical  plexus  begins  on  the  dorsum  of  the  cli- 
toris, by  several  branches  coming  from  it  and  from  the  vulva ; they 
get  into  the  pelvis  under  the  symphysis  pubis,  and  on  the  sides  of 
the  urethra  and  of  the  vagina,  forming  upon  the  lower  part  of  the 
bladder,  and  on  the  side  of  the  vagina,  with  the  assistance  of  branches 
from  these  viscera,  a remarkable  plexus,  which  also  empties  into  the 
internal  iliac  vein. 

The  Plexus  Sacralis  consists  in  an  order  of  veins,  anastomosing 
freely  with  each  other,  and  corresponding  with  the  middle  and  the 
lateral  sacral  veins.  They  communicate  with  the  inferior  end  of  the 
vertebral  sinuses  through  the  anterior  sacral  foramina ; they  also 
communicate  with  the  hemorrhoidal  and  with  the  vesical  veins. 
They  terminate  in  the  venous  trunks,  nearest  the  origin  of  the  ar- 
teries from  which  they  are  derived. 

The  Plexus  Pudendalis  is  derived  from  the  branches  of  the  inter- 
nal pudic  vein  which  go  to  the  perineum,  to  the  posterior  part  of 
the  scrotum,  and  to  the  integuments  of  the  under  part  of  the  penis. 
The  trunk  formed  by  the  assembling  of  these  several  ramifications, 
follows  the  course  of  the  internal  pudic  artery  to  which  it  belongs, 
and  gets  into  the  pelvis  at  the  lower  part  of  the  sciatic  foramen, 
where  it  contributes  to  the  formation  of  the  hypogastric  vein.  ’ 

The  Plexus  Uterinus  consists  in  a considerable  number  of  veins, 
which  are  distributed  upon  the  surface,  and  in  the  texture  of  the 
uterus ; they  are  also  found  in  abundance  in  the  broad  ligaments, 
where  they  anastomose  with  the  ovarial  veins. 

The  Plexus  Vaginalis  comes  from  the  anterior  parts  of  the  organs 
of  generation  constituting  the  vulva,  as  the  labia  majora,  minora, 
and  so  on.  It  also  arises  from  the  whole  surface  of  the  vagina,  sur- 
rounds it  completely,  and  anastomoses  with  the  uterine  veins. 

The  Gluteal,  the  Obturator,  and  the  Ilio-Lumbar  Veins,  also  con- 

26* 


298 


CIRCULATORY  SYSTEM. 


tribute  to  the  Hypogastric. ; their  description  conforms  so  nearly  to 
that  of  the  corresponding  arteries,  that  it  is  unnecessary  to  detail  it. 

The  Primitive  Iliac  Vein,  (Vena  Iliaca  Primitiva , Communis ,) 
formed  by  the  junction  of  the  External  and  of  the  Internal  Iliac, 
extends  from  the  sacro-iliac  symphysis  to  the  lower  margin  of  the 
fourth  lumbar  vertebra,  where  it  joins  the  corresponding  trunk  of 
the  opposite  side  of  the  body,  to  form  the  commencement  of  the 
ascending  vena  cava.  In  this  course  the  left  one  passes  obliquely 
across  the  body  of  the  fifth  lumbar  vertebra,  and  beneath  the  right 
primitive  iliac  artery. 

The  Vena  Cava  Inferior  is  situated  on  the  front  of  the  spinal  co- 
lumn, to  its  right  side,  and  extends  from  the  lower  part  of  the  fourth 
lumbar  vertebra ; or,  in  other  words,  from  the  junction  of  the  primi- 
tive iliac  veins  to  the  under  end  of  the  right  auricle  of  the  heart,  into 
which  it  empties.  It  is  larger  than  the  Descending  Cava. 

In  its  ascent  it  inclines  very  gradually  to  the  right  side  of  the 
spine,  so  as  to  reach  the  opening  in  the  tendinous  centre  of  the  dia- 
phragm, through  which,  it  passes  just  before  it  terminates  in  the 
auricle.  It  is  bounded  on  the  left  side  by  the  aorta  ; and  above  the 
latter  it  is  in  front  of  the  left  crus  of  the  diaphragm.  Its  lower  ex- 
tremity is  crossed  in,  front  by  the  root  of  the  primitive  iliac  artery ; 
it  is  also  crossed  in  its  ascent  by  the  duodenum  and  the  pancreas. 
Its  upper  extremity  is  behind  the  liver,  and  frequently  passes  through 
the  substance  of  this  viscus. 

It  receives  the  middle  sacral,  the  lumbar,  the  spermatic,  the 
emulgent,  the  capsular,  the  hepatic,  and  the  phrenic  veins. 

The  Middle  Sacral  Vein  (Vena  Sacra  Media)  forms,  as  has  been 
just  mentioned  in  the  account  of  the  branches  of  the  hypogastric 
vein,  a part  of  the  sacral  plexus.  Its  trunk  follows  the  course  of 
the  middle  sacral  artery  on  the  front  of  the  sacrum,  and  discharges 
into  the  commencement  of  the  vena  cava,  in  the  fork  formed  by  the 
junction  of  the  primitive  iliacs. 

The  Lumbar  Veins  (Vence  Lumbales ) correspond  with  the  lumbar 
arteries,  and  are  commonly  four  or  five  in  number  on.  each  side. 
Their  primitive  roots  anastomose  with  the  epigastric,  the  last  inter- 
costal, and  the  circumflex  iliac  veins;  the  dorsal  branches  of  them 


VEINS  OF  THE  ABDOMEN. 


299 


also  anastomose  with  the  vertebral  sinuses,  through  the  intervertebral 
foramina.  Their  trunks  pass  along  with  the  arteries,  between  the 
bodies  of  the  vertebrae  and  the  psoas  magnus  muscle,  or  through  the 
fasciculi  of  the  latter : those  on  the  left  side  pass  behind  the  aorta, 
in  order  to  reach  the  vena  cava,  and  are,  consequently,  longer  than 
such  as  are  on  the  right. 

The  Spermatic  Veins  (Vence  Spermaticce.)  The  right  one  extends 
from  the  testicle  to  the  ascending  cava,  just  below  the  emulgent 
veins;  while  the  one  on  the  left  empties  into  the  left  emulgent  vein. 
They  are  larger  than  the  corresponding  arteries,  and  present  some 
peculiarities  in  the  two  sexes. 

In  the  male,  the  extremities  of  these  veins  begin  in  the  testicle, 
and  issue  from  it  through  the  tunica  albuginea  ; some  of  them  also 
arise  from  the  epididymis.  They  anastomose  with  the  superficial 
veins  of  the  penis  and  of  the  scrotum,  and  disengaging  themselves 
from  the  tunica  vaginalis,  at  its  back  part,  are  assembled  into  four 
or  five  anastomosing  trunks  ; which  envelop  the  vas  deferens  and 
the  spermatic  artery,  and  compose  a principal  part  of  the  bulk  of 
the  chord.  Having  passed  through  the  abdominal  canal,  they  are 
reduced  on  each  side  to  one  trunk,  which  creeps  along  the  sper- 
matic artery  on  the  front  of  the  psoas  magnus  muscle,  and  in  com- 
pany with  the  ureter.  Somewhat  below7  the  kidney,  the  spermatic 
vein  is  again  resolved  into  a sort  of  plexus,  having  frequent  addi- 
tions from  the  veins,  in  the  adipose  substance  of  the  kidney,  and 
some  also  from  the  branches  of  the  vena  portarum  in  the  mesentery, 
and  in  the  mesocolon.  It  then  is  reduced  once  more  into  a single 
trunk,  wThich  terminates  as  mentioned.  The  term  Corpus  Pampi- 
niforme  (vine-like)  is,  by  some  anatomists,  limited  to  the  last  plexus 
formed  by  each  spermatic  vein,  but  it  is  also  frequently  extended 
to  both.* 

In  the  female,  the  spermatic  vein  is  not  so  large  as  in  the  male  ; 
it  comes  from  the  ovarium  and  from  the  side  of  the  uterus,  and  is 
joined  by  some  small  branches  from  the  round  ligament  of  the 
uterus,  and  from  the  Fallopian  tube.  Passing  outwardly  between 
the  laminre  of  the  broad  ligament  of  the  uterus,  it  crosses  the  ex- 
ternal iliac  artery,  and  in  the  subsequent  part  of  its  course  is  dis- 
posed of  as  in  the  male. 


* H.  Cloquet,  Trait.  D’Anat. 


300 


CIRCULATORY  SYSTEM. 


The  Emulgent  Veins  ( Vents  Emulgentes,  Renales ) are  commonly 
two  in  number,  one  on  each  side,  and  extend  horizontally  from  the 
fissure  of  the  kidneys  to  the  ascending  cava.  They  are  of  a con- 
siderable size,  and  owing  to  the  position  of  the  vena  cava,  the  left 
is  much  longer  than  the  right,  and  crosses  in  front  of  the  aorta. 
They  open  on  their  respective  sides  of  the  cava  opposite  to  each 
other.  The  branches  of  which  the  emulgent  vein  is  composed, 
coming  from  the  ramifications  of  the  corresponding  artery  in  the 
kidney,  assemble  into  the  single  trunk  near  the  fissure  of  the  kidney  ; 
this  trunk  is  joined  by  some  small  veins  from  the  adjacent  adipose 
matter  and  from  the  capsule  renales,  and  on  the  left  side,  as  men- 
tioned, it  is  also  joined  by  the  spermatic  vein. 

The  Capsular  Veins  (Vents  Capsulares ) arise  from  the  arteries 
spent  upon  the  capsulse  renales ; and  are  two  in  number,  one  on 
each  side.  That  on  the  right  discharges  into  the  vena  cava,  while 
the  one  on  the  left  empties  into  the  left  emulgent  most  frequently. 

The  Hepatic  Veins  ( Vents  Hepaticce)  take  their  rise  in  the  liver, 
and  collect  into  three  principal  trunks,  which  converging  towards 
the  ascending  cava,  discharge  themselves  into  it,  where  it  adheres  to 
the  posterior  margin  of  the  liver,  immediately  below  the  diaphragm. 
Two  of  these  trunks  come  from  the  right  lobe,  and  one  from  the 
left,  moreover,  there  are  several  small  hepatic  veins  wdrich  dis- 
charge themselves  into  the  cava,  and  come  principally  from  the  Lo- 
bulus  Spigelii. 

The  Inferior  Phrenic  Veins  (Vents  Phrenicte  Inferiores)  arise  in 
the  diaphragm,  from  the  corresponding  arteries.  They  are  two  in 
number,  and  discharge  into  the  ascending  cava  just  above  the  he- 
patic veins. 


SECT.  V. — OF  THE  VENA  PORTARUM. 

The  Vena  Portarum  is  derived  from  the  viscera  of  the  abdomen, 
and  presents  the  singularity  of  a vein  ramifying  through  a gland,  the 
liver,  before  its  blood  is  returned  to  the  general  circulation.  The 
arteries  from  which  it  draws  its  supply  of  blood  are  the  superior  and 
the  inferior  mesenteric,  and  the  cceliac  with  the  exception  of  its  he- 


VEINS  OF  THE  ABDOMEN. 


301 


patic  branch.  The  viscera  of  the  abdomen,  which  contribute  to  it 
are  the  spleen,  the  gall-bladder,  the  pancreas,  the  stomach,  the 
small  and  the  large  intestines,  the  large  and  the  small  omentum. 

a.  The  Splenic  Vein  ( Vena  Splenica)  is  formed  by  several  branches, 
which  coming  out  separately  from  the  fissure  of  the  spleen,  unite  after 
a short  course  into  a single  trunk.  This  trunk  runs  in  company  with 
the  splenic  artery  below  it,  along  the  superior  margin  of  the  pan- 
creas, it  is  not  quite  so  tortuous  as  the  artery  itself,  and  proceeding 
from  left  to  right,  is  joined  to  the  superior  mesenteric  Vein  in  front 
of  the  vertebral  column. 

In  this  course,  the  splenic  receives  the  small  veins,*  ( Vents  Breves ,) 
corresponding  with  the  vasa  brevia  of  the  great  end  of  the  stomach, 
and  then,  successively,  several  branches  from  the  pancreas.  It  like- 
wise receives  the  gastric,  or  the  superior  coronary  vein  of  the  sto- 
mach, the  right  gastro-epiploic,  and  the  left  gastro-epiploie  of  the 
same  viscus,  all  of  which  correspond  with  the  arteries  distributed  to 
the  latter. 

b.  The  Inferior  Mesenteric  Vein  ( Vena  Meseraica  Inferior ) corres- 
ponds with  the  inferior  mesenteric  artery,  and,  consequently,  derives 
its  primitive  branches  from  the  rectum  by  the  upper  hemorrhoidal 
veins,  which  anastomose  wuth  the  lower ; from  the  sigmoid  flexure 
of  the  colon  ; and  from  the  left  descending  portion  of  the  latter. 
The  trunk  formed  by  these  branches,  ascends  behind  the  perito- 
neum, between  the  left  ureter  and  the  aorta ; and  going  up  behind  the 
pancreas,  is  discharged  into  the  splenic  vein  an  inch  or  two  from  its 
termination.  But,  like  the  veins  belonging  to  the  lesser  curvature, 
and  the  right  side  of  the  stomach,  it  sometimes  empties  directly  into 
the  vena  portarum,  or  into  the  upper  end  of  the  superior  mesenteric. 

c.  The  Superior  Mesenteric  Vein  ( Vena  Meseraica  Superior ) is  the 
largest  of  the  trunks  which  contribute  to  form  the  vena  portarum. 
It  is  derived  from  the  ramifications  of  the  superior  mesenteric  artery 
upon  the  small  intestines,  the  ileo-colic  valve,  the  right  ascending 
and  the  transverse  colon.  Its  branches  constitute  in  the  mesentery 
and  the  mesocolon  a vascular  intertexture,  forming  arches  and 
meshes  adhering  to  the  corresponding  ones  of  the  arteries.  In  the 
transverse  mesocolon,  it,  like  the  artery,  anastomoses  with  the  infe- 
rior mesenteric  vein.  Its  trunk  being  formed  by  the  union  of  these 

* M.  Bauer  discovered,  in  1824,  valves  in  these  vessels,  contrary  to  the 
general  analogy  of  the  system  of  the  Vena  Portarum.  His  observations  have 
been  confirmed  by  H.  Cloquet. 


302 


CIRCULATORY  SYSTEM. 


several  branches,  ascends  the  mesentery,  and  goes  in  front  of  the 
duodenum,  where  the  latter  crosses  the  spine;  immediately  after- 
wards it  gets,  behind  the  pancreas,  and  near  its  right  end  is  joined 
by  the  splenic  vein.  It  here,  also,  receives  small  branches  from  the 
duodenum,  from  the  pylorus,  and  from  the  gall-bladder. 

The  trunk  of  the  Vena  Portarum  being  formed  behind  the  pan- 
creas by  the  union  of  the  superior  mesenteric  with  the  splenic  vein, 
extends  from  this  point  to  the  transverse  fissure  of  the  liver, 
and  is  about  four  inches  in  length.  It  ascends  obliquely  from 
left  to  right,  behind  the  second  curvature  of  the  duodenum,  being 
bounded  on  the  right  side  by  the  biliary  ducts,  and  on  the  left  by 
the  hepatic  artery  where  it  is  surrounded  by  a great  many  nervous 
filaments  and  lymphatic  vessels,  with  all  of  which  it  is  united  by  a 
common  envelope  of  cellular  substance,  and  of  Peritoneum,  called 
the  capsule  of  Glisson.  Having  reached  the  transverse  fissure  of 
tlie  liver,  it  divides  into  two  branches,  which  are  each  at  a right 
angle  to  it,  but  in  line  with  one  another : they  constitute  the  Sinus 
Portarum,  of  which  the  right  branch  being  spent  upon  the  great  lobe, 
and  the  left  upon  the  small  lobe  of  the  liver,  are  ramified  almost  to  in- 
finity through  the  structure  of  the  latter.  The  terminating  branches 
of  the  vena  portarum  empty  into  the  venae  hepaticae. 

Several  cases  are  recorded  in  the  annals  of  anatomy  in  which  the 
vena  portarum,  instead  of  going  into  the  liver,  discharged  imme- 
diately into  the  ascending  cava.*  In  such  instances  the  hepatic 
artery  is  much  larger  than  usual.  According  to  J.  F.  Meckel,  not- 
withstanding they  are  anomalies,  yet,  as  in  most  other  cases  of  de- 
viation from  the  general  type  of  the  human  family,  a striking  analogy 
may  be  found  between  them  and  what  occurs  in  some  of  the  lower 
orders  of  animals.  Here  the  analogy  exists  with  the  invertebrated 
animals. 

* Lieutaud,  Hist.  Anat.  Med.  Huber,  Obs.  Anat.  p.  34.  Abernethy,  Ph. 
Tr.  1793,  part.  i.  Lawrence,  Med.  Ch.  Trans,  vol.  v. 


PECULIARITIES  OF  THE  FCETUS. 


303 


CHAPTER  IV. 

Of  the  Peculiarities  iu  the  Circulatory  System  of  the  Foetus. 

Owing  to  the  want  of  respiration  in  the  foetus,  its  circulation  is 
conducted  in  a manner  very  different  from  that  of  the  adult.  More- 
over, its  parasitical  life  requires  an  alliance,  through  the  organs  of 
circulation,  with  the  mother.  Its  peculiarities,  therefore,  may  be 
studied  under  two  heads : those  which  arise  from  the  want  of  respi- 
ration, and  those  which  are  required  for  its  nourishment.  The  pe- 
culiarities of  the  first  order  are  situated  in  the  thorax,  and  those  of 
the  second  in  the  abdomen. 


SECT.  I. — OF  THE  PECULIARITIES  OF  THE  FCETUS,  ARISING 
FROM  THE  WANT  OF  RESPIRATION. 

The  Heart,  at  a very  short  period  after  conception,  so  early  as 
about  the  end  of  the  first  month,  is  sufficiently  developed  to  be  in 
a state  of  great  activity.  The  first  indication  of  its  existence,  and, 
indeed,  of  the  life  of  the  new  animal,  is  a small  tremulous  point, 
called  the  Punctum  Saliens,  from  its  incessant  motion.  The  mus- 
cular structure  of  it  is  soon  evolved,  and  in  a few  weeks  becomes 
very  manifest.  At  the  earliest  visible  period  of  the  heart  in  the 
incubated  egg,  which  affords  a satisfactory  analogy,  it  consists  of 
two  vesicles  united  by  a canal,  (Canalis  Auricularis  of  Haller.)  One 
of  the  vesicles  is  the  right  auricle  ; the  other  is  the  left  ventricle,  and 
is  probably  the  first  to  pulsate.  The  aorta  is  also  visible,  as  well  as 
the  venae  cavae.  The  circulation,  at  this  period,  is  very  simple : the 
blood  starting  from  the  left  ventricle,  is  propelled  into  the  aorta  ; it 
is  collected  from  the  ramifications  of  the  last  into  the  two  venae 
cavae,  and  thereby  brought  to  the  right  auricle;  it  is  then  propelled 
by  the  right  auricle  through  the  canalis  auricularis  into  the  left  ven- 
tricle, whereby  its  round  is  completed,  and  it  then  starts  again. 
This  is  the  most  simple  kind  of  circulation,  and  is  found,  in  fact, 
during  the  whole  life  of  such  animals  as  do  not  breathe  by  lungs  ; 


304 


CIRCULATORY  SYSTEM. 


for  example,  fish.  As  the  gills  in  them  take  the  place  of  lungs,  a 
branch  from  the  aorta,  spent  upon  the  gills,  is  sufficient  for  their 
purposes  of  respiration. 

The  terms  right  auricle  and  left  ventricle  have  been  used,  because 
the  cavities  alluded  to  perform  the  functions  of  the  adult  state  ; but 
in  the  progress  of  the  development  of  the  heart,  a partition  begins 
to  show  itself  which  ultimately  divides  each  of  them  into  two  distinct 
chambers,  whereby  we  have  a right  auricle  and  a left  one  ; a left 
ventricle  and  a right  one.  And  the  canalis  auricularis  is  reduced 
from  a canal  into  a short  orifice,  called  Ostium  Venosum,  commu- 
nicating from  the  auricles  to  the  ventricles,  and  which  is  afterwards 
divided  into  two,  one  for  either  side  of  the  heart.  The  partition  be- 
tween the  ventricles  is  completed  about  the  end  of  the  second 
month  of  gestation,  at  a period  when  the  aorta,  from  having  been 
simple  originally,  is  converted  into  two  canals,  one  of  which  be- 
comes the  pulmonary  artery.  The  partition  between  the  auricles 
is  not  completed  till  birth.  In  cases  of  monstrosity,  it  is  interesting 
to  see  how  much  the  heart,  at  the  end  of  uterine  life,  has  still  pre- 
served this  original  type  of  simplicity.  I have  formerly  dissected 
a double  foetus,  where  from  the  parasitical  character  of  one,  no  effort 
had  been  made  for  the  development  of  the  lungs  of  the  latter.  The 
consequence  of  which  was,  the  parasites  heart  consisted  only  of  the 
right  auricle  and  of  the  left  ventricle,  and  the  pulmonary  artery  had 
not  been  formed  at  all,  there  being  but  the  single  tube,  the  aorta, 
which  led  from  the  left  ventricle,  and  had  a sort  of  arrangement  in 
its  branches  depending  upon  the  tendency  to  form  pulmonary  arte- 
ries.* 

At  birth,  the  auricular  septum  has  advanced  so  far  that  the  commu- 
nication between  the  two  cavities  is  kept  up  only  by  a deficiency, 
called  the  Foramen  Ovale.  This  foramen,  marked  by  a depression 
on  the  right  side,  admits  a small  quill,  when  conducted  obliquely 
through  it,  and  is  protected  on  the  left  side  by  a valve,  the  edge  of 
which  is  upwards,  and  which  when  applied,  is  just  large  enough  to 
cover  the  whole  foramen.  The  moment  that  the  blood  ceases  to 
pass  through  the  foramen  ovale,  which  occurs  at  the  first  act  of  in- 
spiration, the  valve  is  applied,  and  the  aperture  grows  up  by  the  ad- 
hesion of  its  edge.  The  mechanism  of  this  process  is  sufficiently 
simple.  So  long  as  the  principal  current  of  the  blood  was  into  the 

* For  a detail  of  this  case,  See  North  American  Medical  and  Surgical 
Journal,  Philad.,  Oct.,  1826. 


PECULIARITIES  OF  THE  FCETUS. 


305 


right  auricle,  the  valve  was  pushed  off  from  the  side  of  the  septum ; 
but  as  breathing  establishes,  through  the  lungs,  pulmonary  veins, 
and  left  auricle,  a current  of  circulation  equivalent,  both  in  quantity 
and  force,  to  that  through  the  two  vense  cavse  and  right  auricle,  a 
perfect  equilibrium  between  the  auricles  is  established,  and  the 
valve  retains  its  place  against  the  septum.  Notwithstanding  the 
incessant  action  of  the  auricles,  during  all  the  subsequent  periods 
of  life,  this  equilibrium,  in  the  force  and  time  of  their  contraction, 
remains  uniform : a circumstance  proved,  conclusively,  by  the  health 
and  strength  of  adults  in  whom  the  valve  has  never  adhered  to  the 
day  of  their  death ; an  observation  made  by  many  anatomists,  and 
of  which  I have  witnessed  several  examples.  In  one  of  them  I 
passed  two  fingers  readily  from  one  auricle  into  the  other,  owing  to 
the  unusual  size  of  the  aperture. 

The  valve  which  closes  the  foramen  ovale  is,  first  of  all,  scarcely 
perceptible;  but  as  the  foetus  advances  in  age,  the  valve  advances 
in  size,  and  is  indeed,  large  enough  to  close  the  foramen  some 
weeks  before  birth.  It  is  formed  from  the  lining  membrane  of  the 
two  auricles,  with  an  intermediate  cellular  substance. 

The  Valve  of  Eustachius,  which  exists  also  in  the  adult  heart,  is 
placed  at  the  anterior  semi-circumference  of  the  orifice  of  the  ascend- 
ing vena  cava  in  the  right  auricle,  one  of  its  ends  adhering  to  the 
anterior  margin  of  the  foramen  ovale.  This  valve,  contrary  to  the 
one  in  the  foramen  ovale,  is  larger  in  proportion  as  the  foetus  is 
younger,  and,  when  first  observed,  covers  the  whole  orifice  of  the 
vena  cava  ascendens;  its  opening,  however,  is  in  the  direction  of 
the  current  of  blood  in  the  latter.  It  also  is  formed  by  a duplica- 
ture  of  the  lining  membrane  of  the  auricle;  and,  from  its  disposition, 
determines  the  blood  of  the  ascending  cava  to  flow  through  the 
foramen  ovale  into  the  left  auricle,  either  wholly  or  in  part,  accord- 
ing to  the  period  of  gestation.  Its  obliquity  also  gives  a direction 
to  the  blood  of  the  descending  cava,  into  the  right  ventricle  from 
the  right  auricle.  These  uses  of  the  Eustachian  valve  were  pointed 
out  by  the  celebrated  Sabatier;*  their  value  will  be  illustrated  here- 
after. 

The  ventricles  of  the  Heart,  at  birth,  have  the  same  structure 
and  internal  arrangement  as  afterwards;  they  are  remarkable,  how- 

* Traite  d’Anat.  vol.  ii.  p.  266. 

Vol.  II.— 27 


306 


CIRCULATORY  SYSTEM. 


ever,  for  being  of  equal  thickness,  or  nearly  so,  an  observation  of 
Mr.  John  Hunter.*  This  fact  is  connected  with  the  circumstance 
of  their  both  contributing  to  the  aortic  circulation  till  respiration 
begins,  owing  to  the  pulmonary  artery  entering,  during  foetal  life, 
by  its  largest  branch,  into  the  aorta. 

The  Ductus  Arteriosus  constitutes  this  branch  of  the  pulmonary 
artery,  and  is,  in  fact,  the  continuation  of  the  trunk  of  the  latter  into 
the  aorta,  immediately  behind  the  origin  of  the  left  subclavian 
artery.  The  right  and  the  left  pulmonary  artery  at  this  period,  are 
but  inconsiderable  trunks,  incapable  by  any  means  of  carrying  off 
all  the  blood  of  the  right  ventricle ; the  greater  part  of  it,  therefore, 
is  conveyed  by  the  ductus  arteriosus  into  the  descending  aorta.  As 
the  contraction  of  the  ventricles,  like  that  of  the  auricles,  is  synchro- 
nous, it  is  evident  that  the  column  of  blood  in  the  descending  aorta, 
is  acted  upon  by  both  ventricles  at  the  same  moment. 

The  ductus  arteriosus  preserves  the  principle  of  a single  circula- 
tion in  the  foetus,  which  was  first  of  all  manifested  by  the  two  ven- 
tricles, constituting  but  one  cavity,  and  by  the  aorta  and  pulmonary 
artery  being  but  one  trunk.  At  the  first  act  of  inspiration  the  lungs, 
which  were  before  solid,  and  the  thorax,  which  was  compressed, 
are  greatly  augmented  in  volume  by  the  introduction  of  air.  The 
dilatation  of  the  thorax,  besides  introducing  air  through  the  trachea, 
causes  an  increased  flow  of  blood  through  the  right  and  left  pulmo- 
nary arteries,  in  order  to  fill  the  vacuum  in  the  lungs.  The  pulmo- 
nary arteries  become  in  that  way  permanently  dilated,  and  the  cir- 
culation is  finally  drawn  off  entirely  from  the  ductus  arteriosus, 
though  this  takes  several  weeks  or  months  before  it  is  completely 
accomplished.  The  ductus  arteriosus  in  this  time  is  continually 
contracting,  and  is  at  length  converted  into  a ligamentous  chord, 
like  other  arteries,  whose  circulation  has  been  arrested. 

These  are  the  several  peculiarities  which  distinguish  the  foetal 
circulation,  owing  to  the  privation  of  respiration;  and  it  is  clear, 
that  the  collective  result  is  that  of  a circulation  quite  as  simple  as 
if  the  heart  consisted  of  but  two  cavities;  while,  at  the  same  time, 
it  keeps  this  organ  in  a state  of  preparation  for  carrying  on  two  dis- 
tinct circulations,  one  pulmonary  and  the  other  aortic,  from  the 


* Animal  Economy. 


PECULIARITIES  OF  THE  FCETUS. 


307 


moment  that  respiration  begins:  so  that  the  whole  mass  of  blood  is, 
in  subsequent  life,  brought  successively  under  the  influence  of  res- 
piration, by  having  to  pass  unavoidably  through  the  lungs. 

SECT.  II. — OF  THE  PECULIARITIES  OF  THE  CIRCULATION  OF 
THE  FCETUS  CONNECTED  WITH  ITS  NOURISHMENT. 

The  Umbilical  Vein,  one  of  the  constituents  of  the  umbilical 
chord,  brings  the  blood  from  the  placenta  to  the  fcetus.  This  vessel 
is  from  three  to  four  lines  in  diameter,  and  enters  at  the  navel; 
thence  it  goes  along  the  free  margin  of  the  suspensory  ligament  of 
the  liver,  and  traverses  the  anterior  half  of  the  umbilical  fissure,  to 
terminate  in  the  left  branch  of  the  sinus  of  the  vena  portarum.  In 
this  course  through  the  liver,  the  umbilical  vein  sends  off  to  the 
right  and  the  left  lobe,  several  small  branches.  As  the  intestinal 
circulation  of  the  foetus  is  too  small  to  send  much  blood  through 
the  vena  portarum,  it  would  be  sufficiently  correct  to  consider  the 
sinus  venae  portarum  as  the  bifurcation  of  the  umbilical  vein : but, 
as  this  might  introduce  a confusion  into  the  description,  it  will  be 
better  to  retain  the  adult  nomenclature. 

The  Ductus  Venosus  is  a vein  which  occupies  the  posterior  half 
of  the  umbilical  fissure,  and  is  about  a line  and  a half  in  diameter. 
It  arises  from  the  left  branch  of  the  sinus  portarum,  opposite  to  the 
place  where  the  umbilical  vein  entered  or  terminated,  and  is  con- 
sequently in  the  same  line  with  the  latter.  Traversing  the  posterior 
part  of  the  umbilical  fissure,  it  terminates  in  the  left  vena  hepatica, 
as  this  hepatic  vein  is  about  joining  the  ascending  cava,  just  be- 
low the  tendinous  centre  of  the  diaphragm.  Through  this  route 
much  of  the  blood  of  the  umbilical  vein  is  carried  directly  to  the 
right  auricle  of  the  heart,  and  then  passed  through  the  foramen 
ovale  into  the  left  auricle  by  the  mechanism  of  the  Eustachian 
valve. 

From  these  considerations,  it  is  evident  that  the  umbilical  vein 
really  performs  the  office  of  a vein  till  it  reaches  the  liver,  but  that  there, 
much  of  its  blood  is  spent  through  the  portal  circulation,  upon  the 
structure  of  this  viscus  ; and  that  what  remains  is  carried  through  the 
ductus  venosus  to  the  heart.  Like  other  veins,  it  is  furnished  with 


308 


CIRCULATORY  SYSTEM. 


valves,  of  which  there  are  two  ; one  at  its  termination  in  the  sinus 
portarum,  and  the  other  at  the  cardiac  extremity  of  the  ductus  veno- 
sus.* The  establishment  of  respiration,  by  putting  the  circulation 
into  other  channels,  likewise  causes  its  obliteration  and  final  conver- 
sion into  a ligamentous  chord.  The  valve,  at  the  sinus  portarum, 
prevents  the  blood  from  taking  a retrograde  course,  and  thereby  keep- 
ing the  umbilical  vein  open  ; the  valve  of  the  ductus  venosus  has  the 
same  effect  upon  the  duct  to  which  it  belongs,  and  is  aided  by  the 
current  of  blood  in  the  left  branch  of  the  sinus  portarum,  setting 
across  the  mouth  of  the  ductus  venosus  instead  of  plunging  into  it 
from  the  umbilical  vein,  as  in  foetal  life. 

It  is  worthy  of  remark,  that  the  left  branch  of  the  sinus  portarum 
is  bounded,  on  its  right  extremity,  by  the  end  of  the  vena  portarum, 
and  receives,  about  its  middle,  the  umbilical  vein.  In  the  space, 
then,  between  the  umbilical  vein  and  the  portal,  the  circulation, 
from  the  predominance  of  umbilical  blood  in  foetal  life,  is  conducted 
from  left  to  right,  but  afterwards  from  right  to  left,  as  the  portal  cir- 
culation is  established  and  the  other  is  arrested. 

The  Umbilical  Arteries  discharge  the  important  office  of  conduct- 
ing the  effete  blood  of  the  fcetus  to  the  placenta.  They  are  the  con- 
tinuations of  the  internal  iliacs,  and  are  two  in  number,  one  on  either 
side ; they  conduct  off  so  much  of  the  blood  of  the  primitive  iliacs, 
as  to  leave  the  external  iliacs  of  a very  small  size.  During  the  early 
months  of  uterine  life,  they  are  rather,  indeed,  the  continued  trunks 
of  the  primitive  i acs  ; the  branches  from  the  latter  being  then  so 
little  developed  as  to  appear  quite  subordinate  to  the  chief  function, 
of  carrying  the  blood  out  of  the  fcetus,  to  the  placenta.  But  as  the 
inferior  extremities  and  the  buttocks  grow,  these  subordinate  branches 
are  more  and  more  evolved. 

At  birth,  the  umbilical  arteries,  after  dipping  very  superficially  into 
the  pelvis,  rise  up  at  the  sides  of  the  bladder  and  converge  towards 
the  navel.  They  emerge  at  the  latter,  cling  together  and  traverse 
the  umbilical  chord  by  twisting  spirally  around  the  umbilical  vein, 
like  two  small  strings  wound  in  this  wray  upon  a larger  one.  Their 
diameter  is  from  a line  to  a line  and  a half.  They  anastomose  as 
they  join  the  placenta,  but  not  previously. 

Like  the  circulation  between  arteries  and  veins  in  other  parts  of 
the  body,  the  capillaries  of  the  umbilical  arteries  terminate  in  those 


* Bichat,  Anat.  Descrip,  vol.  v.  p.  419. 


PECULIARITIES  OF  THE  FCETUS. 


309 


of  the  umbilical  vein  in  the  placenta.  From  the  observations  of 
Wrisberg,  Osiander  and  the  highly  distinguished  Professor  Chapman 
of  the  University  of  Pennsylvania,  it  seems  that  there  is  no  direct 
vascular  communication  between  the  mother  and  the  foetus. 

This  opinion  is  founded  upon  the  leading  facts,  that  the  finest  injec- 
tions do  not  pass  from  one  to  the  other  ; that  foetuses,  after  the  death  of 
the  mother  from  haemorrhage,  still  live  and  retain  their  usual  quantity 
of  blood  ; that  if  the  foetus  be  expelled  entire  with  the  placenta  and 
membranes  unhurt,  the  circulation  still  continues.  One  example  of 
which  was  witnessed  nine  minutes  by  Wrisberg;*  another  fifteen  by 
Osiander  ;f  some  from  ten  to  twenty  minutes  by  Professor  Chap- 
man another  for  an  hour  by  Professor  Channing  of  Boston,  and 
Dr.  Selby  of  Tennessee, § where  a bath  of  tepid  water  was  used 
to  resuscitate  the  foetus.  Also,  from  the  observations  of  Breschet,  it 
seems  that  the  globules  of  the  blood  of  the  foetus,  when  inspected 
by  the  microscope,  are  different  in  appearance  from  those  of  the 
mother.  || 

Mascagni  says  that  he  has  made  several  most  minute  injections 
of  the  pregnant  uterus,  so  as  to  cover  with  small  vessels  its  whole 
internal  surface,  and  to  return  the  injection  by  the  uterine  veins : and 
yet  he  has  never  succeeded  in  injecting,  in  that  way,  the  secun- 
dines.^ 

I have,  myself,  repeatedly  tried  by  minute  injection  to  pass  arti- 
cles from  the  foetal  into  the  maternal  vessels,  and  the  reverse,  but  al- 
ways without  success ; in  two  instances,  the  experiment  was  upon 
human  subjects,  and,  in  the  others,  on  the  cow.  In  one  of  the  lat- 
ter, I perceived  that  some  of  the  injecting  matter  thrown  into  the 
fcetal  vessels  had  got  into  the  uterine  veins ; but  as  the  observation 
was  in  opposition  to  all  the  others,  and  solitary,  I have  no  disposi- 
tion to  array  it  against  them,  at  least,  until  farther  and  more  decided 
experience.  My  second  experiment  on  the  human  subject  was 
made  in  April,  1833,  under  the  following  circumstances : A white 
female,  aged  24,  died  at  the  Alms  House,  suddenly,  and  in  the 
ninth  month  of  pregnancy  ; the  foetus  was  still  in  utero,  but  the  mem- 
branes were  ruptured.  In  the  presence  of  several  of  the  physicians 
and  students,  and  with  the  assistance  of  my  young  friend,  Dr.  God- 

* Meckel,  Man.  D’Anat.  vol.  iii.  p.  163.  f Id. 

f Chapman’s  Med.  and  Phys.  Journal,  vol.  i.  p.  6.  § Id. 

||  Am.  Med.  Jour.  vol.  i.  p.  193. 

H Prodromo,  vol.  i.  p.  127. 


27* 


310 


CIRCULATORY  SYSTEM. 


dard,  to  whose  suggestions  and  manipulations  I am  indebted  for  the 
chemical  compounds  resorted  to,  I injected  through  the  aorta  one 
gallon  of  the  saturated  solution  of  Prussiate  of  potash,  and  followed 
it  with  an  equal  quantity  of  a saturated  solution  of  sulphate  of  iron. 
The  injection  penetrated  very  minutely,  as  might  be  expected,  and 
the  precipitate  of  Prussian  blue  coloured  deeply  many  parts  of  the 
skin.  On  dissecting  the  uterus,  the  uterine  arteries  were  found  well 
injected,  but  the  injection  did  not  reach  the  umbilical  vein  or 
arteries,  as  was  proved  both  by  simple  inspection  and  by  chemical 
tests. 

Having  cut  out  the  uterus  and  taken  it  to  the  University,  the  ex- 
periment Avas  continued  the  next  day  in  the  presence  of  a large  con- 
course of  students  and  several  physicians.  The  umbilical  vessels 
were  first  of  all  injected  with  a saturated  solution  of  bichromate  of 
potash,  and  then  with  a saturated  solution  of  sugar  of  lead.  The 
result  was  a strong,  yellow  precipitate,  the  bichromate  of  lead.  The 
injection  passed  reciprocally  from  the  arteries  into  the  vein,  and 
from  the  vein  into  the  arteries,  conformably  to  the  direction  in 
which  it  was  thrown  for  the  time.  The  sinuses  of  the  uterus  were 
then  injected  with  similar  materials  to  those  of  the  uterine  arteries ; 
to  wit,  a solution  of  Prussiate  of  potash,  followed  by  one  of  sulphate 
of  iron. 

The  umbilical  vessels  were  then  all  filled  with  liquid  plaster  of 
Paris  coloured  yellow:  and  the  uterine  sinuses  with  liquid  plaster  of 
Paris  coloured  blue,  of  which  they  readily  received  eighteen  ounces. 
A short  time  having  been  allowed  for  the  setting  of  the  injection,  I 
cut  into  the  substance  of  the  uterus  and  of  the  placenta.  No  yellow 
injection  was  found  in  the  vessels  of  the  uterus,  nor  was  there  any 
blue  injection  found  in  the  umbilical  vessels  of  the  placenta ; there 
Avas,  therefore  a deficiency  of  evidence  of  direct  vascular  communi- 
cation between  the  foetus  and  the  mother.  The  placenta  was  infil- 
trated with  Prussiate  of  iron,  and  considerable  quantities  of  blue 
plaster  were  found  in  the  cavity  of  the  uterus. 

In  the  progress  of  the  injection  with  the  Prussiate  of  iron,  into  the 
uterine  sinuses,  the  membranes  were  raised  from  the  uterus  in  vesi- 
cations. 

The  parts,  having  been  distended  and  put  aside  to  dry,  at  the 
end  of  a fortnight  they  were  examined  again  by  incisions,  and  the 
same  evidence  of  the  want  of  direct  vascular  communication  was 
renewed.  But  the  placenta  was  found  to  be  infiltrated  according  to 
certain  rules  seeming  to  depend  on  its  organization.  The  blue 


PECULIARITIES  OF  THE  FCETUS. 


311 


colouring  matter  on  the  part  of  the  uterus,  and  the  yellow  on  the 
part  of  the  foetus,  determined  in  it  two  parts,  one  uterine  and  the 
other  foetal,  closely  and  alternately  interlocked,  like  a dove-tailing  : 
the  uterine  processes  passed  to  within  a short  distance  of  the  free 
surface  of  the  placenta,  while  the  foetal  processes  went  almost  to  the 
base  of  the  placenta.  The  confines  of  the  two  colours  were  defined 
well  by  this  abrupt  termination,  the  borders  of  these  dove-tails.  The 
appearance  would,  perhaps,  be  better  designated  by  the  terms  uterine 
lobes,  and  foetal  lobes,  alternately  penetrating,  so  as  to  constitute 
the  whole  mass  of  the  placenta.  No  distinct  vessel  of  a blue  colour 
could,  however,  be  seen  in  the  uterine  lobes ; but  a few  very  spare 
yellow  ones  were  visible.  On  raising  up  these  uterine  divisions, 
the  orifices  of  the  uterine  sinuses  were  seen  at  their  base. 

The  inference  from  this  experiment  is,  that  though  there  is  no 
direct  connexion  of  blood  vessels  between  the  mother  and  the 
foetus,  yet  there  is  a part  of  the  placenta  which  seems  to  hold  a 
special  connexion  with  the  uterine  sinuses,  and  which  may  possibly, 
therefore,  by  interstitial  circulation,  establish  a connexion  with  the 
foetus.  The  facts  are  at  any  rate  presented  as  they  occurred. 

The  effete  blood  of  the  umbilical  arteries  becomes  regenerated  in 
the  placenta,  assumes  a brighter  hue,  and  is  returned  to  the  foetus  by 
the  umbilical  vein.  According  to  the  theory  of  Sabatier  concerning 
the  use  of  the  Eustachian  valve,  if  the  latter  did  not  exist,  the  fresh 
blood  brought  to  the  heart  by  the  ductus  venosus,  instead  of  being 
diverted  into  the  left  auricle  through  the  foramen  ovale,  would  be 
received  by  the  right  auricle,  and  transmitted,  either  wholly  or  in  a 
great  degree,  into  the  right  ventricle.  It  would  then  be  passed  from 
the  latter  through  the  pulmonary  artery  and  ductus  arteriosus  into  the 
descending  aorta,  so  that  no  part  of  the  system,  above  the  junction 
of  the  duct  with  the  aorta,  could  receive  the  benefit  of  it : this  would 
leave  the  head  and  upper  extremities  unsupplied  with  fresh  blood. 
Moreover,  much  of  the  latter  would  be  fruitlessly  introduced,  for  it 
would  depart  almost  immediately  through  the  umbilical  arteries. 
But  the  Eustachian  valve  determining  the  flow  of  blood  of  the 
ascending  cava  into  the  left  auricle,  its  passage  into  the  left  ventricle 
is  a matter  of  course  : thence  it  begins  the  aortic  circulation  fairly,  so 
that  every  part  of  the  system  participates  in  its  benefits. 

The  celebrated  Wistar*  has  also  happily  suggested,  that  without 

* System  of  Anat.  vol.  ii.  p.  76,  3d  edition. 


312 


ABSORBENT  SYSTEM. 


this  arrangement,  the  blood  of  the  coronary  arteries  of  the  heart  itself, 
the  purity  of  which  is  so  essential  to  the  vigour  of  circulation,  would 
otherwise  have  been  effete,  and,  consequently,  unlit  for  its  object  of 
refreshing  the  heart. 

The  umbilical  arteries  become  the  round  ligaments  of  the  blad- 
der, after  the  circulation  through  them  has  ceased,  with  the  excep- 
tion of  their  pelvic  extremities,  which  subsequently  constitute  the 
trunks  of  the  Internal  Iliac  Arteries. 


CHAPTER  V. 

Histology  of  the  Absorbent  System. 

The  Absorbent  System  is  one  of  the  most  interesting  of  those 
which  compose  the  human  body,  both  on  account  of  its  very  gene- 
ral diffusion,  and  of  the  office  of  interstitial  absorption  that  it  inces- 
santly carries  on,  thereby  removing  the  effete  parts  of  the  body  and, 
making  room  for  the  deposite  of  new  ones.  It  is  also  called  the 
lymphatic  system,  owing  to  the  transparent  colour  of  the  fluid  which 
it  conducts. 

With  the  exception  of  an  imperfect  observation  of  some  of  these 
vessels  in  the  mesentery  of  a goat,  by  Herophilus  and  Erasistratus,. 
during  the  reigns  of  the  Ptolemies  in  Egypt,  280  years  before  Christ, 
what  is  known  of  them  is  entirely  a modern  acquisition  in  anatomy. 
In  1564,  Eustachius  discovered  the  thoracic  duct  of  a horse,  which 
in  the  ignorance  of  its  use,  he  called  vena  alba  thoracis.  This  fact 
remained  insulated  and  almost  forgotten  for  seventy  years.  In  1622, 
Asellius  discovered  the  absorbents  of  the  mesentery,  and  in  the  dis- 
cussions consequent  thereto,  the  original  observation  of  Herophilus 
and  Erasistratus  was  relieved  from  an  oblivion  of  nineteen  centuries, 
to  be  again  brought  to  light  and  admired.  Asellius  seems  to  have 
understood  that  the  absorbents  of  the  mesentery  collect  the  chyle 
from  the  intestines,  but  his  knowledge  ceased  there,  for  he  thought 


\ 


LYMPHATIC  VESSELS. 


313 


that  they  discharged  into  the  vena  port  arum.*  In  1634,  Weslingius 
saw  the  thoracic  duct  again ; and  in  1649,  ascertained  that  the  chy- 
liferous  vessels  of  Asellius  terminated  in  it.  In  1650,  Olaus  Rud- 
beck,  a young  man  pursuing  his  anatomical  studies  in  Leyden,  saw 
first  the  lymphatic  vessels  of  the  liver,  and  in  a few  months  after- 
wards injected  similar  ones  in  the  loins,  in  the  thorax,  in  the  groins, 
and  in  the  arm-pits.  Thomas  Bartholine,  a teacher  of  great  reputa- 
tion in  those  days,  in  a dissertation,  dated  in  1652,  claimed  for  him- 
self the  priority  of  these  observations,  and  from  the  obscurity  of 
Rudbeck,  enjoyed  for  some  time  the  merit  of  them.  In  1654, 
Rudbeck  published  and  set  forth  his  own  pretensions  with  such 
force,  that  he  finally  triumphed  over  his  antagonist,  but  not  until 
the  whole  world  of  anatomy  had  been  set  in  commotion ; one  party 
being  for  the  professor,  and  the  other  for  the  pupil,  and  many  bloody 
strifes  having  arisen  between  the  students  of  the  respective  sides. 
In  1653,  Jolyff,  a celebrated  anatomist,  of  London,  proclaimed  his 
own  rights  to  this  wTarmly  contested  honour ; but  the  period  being 
rather  late,  his  name  is  scarcely  associated  with  the  history  of  these 
feuds.  Almost  a century  then  passed  before  there  were  many  im- 
portant additions  to  the  knowledge  of  those  times.  After  which 
great  contributions  were  made  by  Dr.  A.  Monro, f Dr.  W.  Hunter, X 
Hewson,§  and  Cruikshank,||  but  chiefly  by  the  celebrated  Mascagni, IT 
who,  having  imagined  finely  pointed  instruments  of  glass  for  exe- 
cuting his  injections  of  these  vessels,  succeeded  in  demonstrating 
them  in  almost  every  part  of  the  body,  excepting  the  spinal  marrow, 
the  brain,  the  ball  of  the  eye,  and  perhaps  the  placenta.  In  some  of 
these  parts,  however,  he  says  he  has  seen  them,  and  he  speaks  con- 
fidently of  their  existence,  without  exception,  every  where,  even  in 
the  enamel  of  the  teeth.** 

The  Lymphatic  Vessels  are  small,  pellucid,  transparent,  cylin- 

* It  is  somewhat  remarkable,  that  the  celebrated  Harvey,  who  had  himself 
so  much  to  complain  of,  in  the  obstinacy  with  which  his  cotemporaries  adhered 
to  ancient  errors,  for  thirty  years  resisted  the  discovery  of  Asellius,  and  died, 
finally  protesting  against  it. 

f He  Yenis  Lymphat.  Valv.  Berlin,  1757-70. 

X Med.  Comment.  London,  1762-77. 

§ Experimental  Inquiries,  London,  1774-77. 

||  Anat.  of  the  Lymphatics,  London,  1774-90. 

If  Vasor.  Lymph.  Corp.  Hum.  Historia  et  Ichnographia.  Sienna.  1787. 

**  Prodromo  della  Grande  Anatomia,  vol.  i.  p.  1. 


314 


ABSORBENT  SYSTEM. 


drical  tubes,  generally  of  about  a line  or  less  in  diameter,  whose 
trunks  have  been  traced  to  all  the  external  and  internal  surfaces  of 
the  body,  and  to  the  depth  of  all  the  organs,  with  the  exceptions 
stated.  It  is  only  lately,  however,  that  their  existence  on  the  ex- 
ternal surface  of  the  skin  has  been  put  beyond  doubt,  by  the  ob- 
servations and  injections  of  M.  Lauth.*  Their  origin  is  so  attenu- 
ated, that  anatomists  have  come  to  no  satisfactory  conclusion  in 
regard  to  its  manner. 

The  visible  origin  of  the  absorbents  is,  in  some  'parts,  as  in  the 
intestinal  canal  and  on  the  glans  penis,  according  to  Breschet,  as  a 
reticulated  intertexture,  the  meshes  of  which  are  so  close  as  to  leave 
scarcely  an  interval  between  them.  In  the  peritoneal  coat  of  the 
liver  this  reticulation  is  so  fine  and  close  that  the  membrane  appears 
to  be  composed  wholly  of  them : their  connexion,  however,  with 
the  deeper  absorbents  is  so  free  that  they  cannot  be  preserved  in  this 
state  owing  to  the  subsidence  of  the  injection,  especially  if  it  be 
mercury.  Professor  Fohman,  of  Heidelberg,  whose  injections  are 
said  to  be  of  a most  superior  kind,  is  of  opinion  that  in  many  cases 
these  vessels  have  a cellular  origin,  such  at  least  is  the  appearance 
of  those  in  the  cornea  and  in  the  umbilical  chord  injected  by  him. 
Muller,  however,  doubts  the  accuracy  of  his  conclusions  in  regard 
to  the  character  of  these  cells. f Fohman  is  indeed  of  opinion  that 
cellular  substance  consists  merely  of  lymphatics. 

The  earlier  cultivators  of  this  branch  of  study,  not  knowing  their 
absorbent  properties,  conceived  them  to  be  continuations  of  the  arte- 
ries applied  to  the  reconducting  of  the  serous  part  of  the  blood  to 
the  heart ; and  considered  the  opinion  substantiated  by  the  circum- 
stance of  their  being  occasionally  filled  by  fine  injections  thrown 
into  the  arteries.  More  improved  views  of  their  uses  caused  the 
abandonment  of  this  theory,  and  the  substitution  of  their  absorbing 
powers  ; in  wThich  case  the  minds  of  anatomists  became  divided  be- 
tween the  ampulla-like  mouth,  or  wide  patulous  origin  of  Lieber- 
kuhn,  and  the  small  orifices  of  Hewson. 

It  is,  perhaps,  not  possible  to  solve  the  question  in  regard  to  the 
mode  of  origin  of  the  lymphatics,  at  least,  in  most  parts  of  the  body. 
Meckel,  about  the  middle  of  the  last  century,  asserted  their  conti- 
nuity with  the  veins.  Mr.  Ribes  has  seen  matter  injected  into  the 
vena  portarum  find  its  way  into  the  lymphatics  of  the  liver.  On 

* Essai  sur  les  Vaisseaux  Lymph.  Strasburg,  1824. 

f Loc.  cit.  p.  283. 


LYMPHATIC  VESSELS. 


315 


this  subject,  M.  Chaussier  says,*  that,  ignorant  of  the  manner  in 
which  the  arteries,  veins,  nerves,  and  lymphatics,  arrange  them- 
selves collectively  into  a glandular  structure,  or,  in  other  words, 
into  a capillary  system,  we  cannot  avoid  ignorance  of  the  part  acted 
by  the  lymphatics  alone  ; we  only  know  that  the  minute  lymphatics 
form  a portion  of  the  elements  of  each  viscus  and  structure  of  the 
body,  and  that  they  only  become  visible  in  becoming  larger  trunks. 

The  absorbents  in  proceeding  from  their  origins,  in  general  be- 
come larger  and  less  numerous,  and  form  frequent  anastomoses 
with  one  another.  The  proportionate  increase  of  magnitude  from 
the  successive  junction  of  trunks  is  by  no  means  equal  to  what  oc- 
curs in  the  veins.  The  larger  superficial  absorbent  trunks  of  the 
extremities  have  not  so  much  disposition  to  run  into  one  another, 
hence  they  retain  a size  almost  uniform  from  one  end  of  the  limb  to 
the  other.  When  fully  distended,  the  appearance  of  absorbents  is 
not  regularly  cylindrical,  but  knotted,  owing  to  the  frequent  valvular 
interruptions  in  their  cavities.  The  absorbents  from  all  parts  of  the 
body,  are  finally  united  into  two  tubes ; one  on  the  left,  and  the 
other  on  the  right  side  of  the  trunk  of  the  body,  and  which  dis- 
charge their  contents  into  the  venous  system,  each  on  its  respective 
side,  at  the  junction  of  the  internal  jugular  and  the  subclavian  vein. 
The  trunk  on  the  right  side  receives  the  lymphatics  of  the  right  side 
of  the  head  and  neck,  of  the  right  lung,  and  right  superior  extremity  ; 
while  the  trunk  on  the  left,  called  the  thoracic  duct,  receives  all  the 
chyliferous  vessels  and  the  lymphatics  of  the  remaining  part  of  the 
body.  It  would  appear,  from  the  observations  of  the  younger 
Lauth,f  that  there  are  also  other  terminations  of  the  lymphatics  in 
the  veins ; to  wit,  such  as  in  the  }ret  capillary  state  end  in  the  veins 
of  the  minute  structure  of  organs,  and  such  as  empty  into  them  in 
the  interior  of  the  lymphatic  glands.  Previously  to  Lauth,  this  senti- 
ment of  communication  with  the  veins  was  strongly  advocated  by 
several  anatomists  and  physiologists,  for  the  following  reasons:  1. 
That  the  known  roots  of  the  lymphatic  system  have  an  area  much 
superior  to  that  of  the  trunks  in  which  they  terminate.  2.  That 
substances  introduced  into  certain  lymphatics  by  absorption  or  in- 
jection, have  been  found  in  the  contiguous  veins.  3.  That  a liga- 
ture upon  the  thoracic  duct  produced  death  only  after  ten  or  fifteen 
days,  and  then  the  articles  which  had  been  absorbed  by  the  intestines, 

* Diet,  des  Sciences  Med.  Art.  Lymphatiques. 

^ f Loc.  cit. 


316 


ABSORBENT  SYSTEM. 


were  found  in  the  blood.  4.  And  that  injections  had  proved  this 
communication. 

Notwithstanding  the  well  known  fact  of  injections,  under  certain 
circumstances,  passing  from  the  arteries  into  the  lymphatics,  some 
anatomists  of  modern  date  have  hesitated  in  admitting  a direct 
communication.  M.  Meckel  has,  indeed,  rejected  the  notion  en- 
tirely, on  the  ground  that  the  fluid  contained  in  the  trunks  of  the 
absorbents  is  always  the  same  as  one  finds  at  their  commencement. 
For  example,  the  lymphatics  coming  from  the  liver  contain  a fluid 
like  bile;  those  which  come  from  the  mammae  contain  a fluid  like 
milk;  those  which  come  from  parts  suffering  from  an  extravasation 
of  blood  contain  a sanguineous  fluid;  the  bronchial  glands  are 
coloured  by  the  black  pigment  brought  to  them  from  the  lungs ; 
poisonous  matter,  as  that  of  the  small-pox  or  venereal,  irritates  and 
inflames  the  lymphatics  that  lie  in  the  course  of  its  introduction  into 
the  system.  For  these  reasons  it  would  appear  to  him,  that  the 
arteries  do  not  continue  themselves  into  the  lymphatics  as  they  do 
into  the  veins.  The  observations  of  M.  Lauth  seem  to  have  proved 
the  point,  that  some  of  the  lymphatics  take  their  origin  from  the  in- 
ternal surface  of  the  arteries;  and  it  may  be  through  them  that  in- 
jections have  been  forced  from  one  system  into  the  other.  In  the 
case  of  the  liver  of  a child,  I have  injected  its  absorbents  very 
successfully  from  the  arteries. 

The  coats  of  the  lymphatics  generally  are  too  thin  and  transparent 
for  an  investigation  of  their  structure ; but  as  those  of  the  thoracic 
duct  are  sufficiently  thick  for  the  purpose,  one  may  estimate  the 
structure  of  other  trunks  by  it.  It  is  thus  ascertained  that  they 
consist  of  twTo  coats,  an  internal  and  an  external  one.* 

The  external  coat  is  somewhat  irregular  on  its  surface,  from  its 
connexion  with  the  adjacent  cellular  substance;  and  has  a filamen- 
tous appearance  more  deeply,  which  has  been  considered  as  fibrous, 
or  muscular,  by  some  anatomists,  owing  to  its  contraction  upon  the 
application  of  certain  stimulants.  The  internal  membrane  is  ex- 
tremely fine  and  perfectly  transparent,  and  is  remarkable  for  its  fre- 
quent duplications,  whereby  a system  of  valves  is  produced  re- 
sembling those  of  the  veins.  These  valves  are  generally  of  a 
semi-lunar  or  parabolic  shape,  and  are  arranged  in  pairs,  though 
according  to  Lauth, f some  of  them  are  circular,  and  do  not  close 

* Valentin  asserts  that  there  is  also  a middle  coat,  and  Henle  that  there  is 
an  internal  epithelium. 

f Loc.  cit. 


LYMPHATIC  VESSELS. 


317 


the  canal  entirely.  The  pairs  are  not  placed  at  stated  distances 
from  one  another,  but  vary  in  different  parts  of  the  body ; in  some 
places  there  are  several  in  the  course  of  an  inch,  and  in  others  not 
one  pair.  As  a general  rule,  they  are  less  frequent  as  the  trunk 
increases  in  magnitude;  hence,  the  thoracic  duct  has  but  very  few 
of  them.  The  valves,  by  having  their  semi-circumference  fixed, 
while  the  diameter  is  loose  and  inclined  in  the  course  of  the  circu- 
lation, prevent  the  retrograde  movement  of  the  contained  fluid.  An 
enlargement  of  the  trunk  at  their  outer  face  into  sinuses,  resembling 
those  at  the  valves  of  the  veins,  gives  also  to  the  lymphatic  trunk 
a knotted  condition  when  it  is  fully  injected. 

The  coats  of  the  lymphatic  vessels,  though  very  thin,  are  yet 
dense  and  extremely  strong,  much  more  in  proportion  than  those  of 
any  other  tubes.  They  are  both  extensible  and  elastic,  possess 
striking  powers  of  spontaneous  contraction  in  the  living  body,  and 
also  contract  in  the  dead,  but  to  a less  extent.  They  are  furnished 
with  arteries  and  veins,  and  probably  with  nerves  also,  from  their  sen- 
sibility in  a state  of  inflammation.  And,  as  they  stand  in  need  of 
a similar  organization  with  other  canals,  their  parietes  are  said  also 
to  have  lymphatics. 

The  absorbent  vessels,  are,  by  some,  divided  into  lacteals  and 
lymphatics,*  the  first  term  expressing  those  which  convey  the  chyle 
from  the  intestines,  and  the  second  such  as  are  found  in  other  parts 
of  the  system.  As  the  difference  is  more  in  the  fluid  conducted 
than  in  the  structure  of  the  vessels  themselves,  the  division  is  rather 
superfluous.  There  is  also  a distinction  of  the  lymphatics,  as  in 
the  veins,  arising  from  their  situation;  some  of  them  are  called  su- 
perficial, and  the  others  deep-seated.  The  arrangement  upon  which 
this  nomenclature  depends,  is  found  in  the  head,  trunk,  extremities, 
and  in  most  of  the  viscera.  The  deep-seated  trunks  are  the  largest. 
They  are  the  least  numerous  in  the  muscular  parts  of  the  body. 

* This  division  has  been  handed  down  from  the  time  of  Bartholine,  who, 
not,  suspecting-  the  absorbing  powers  of  the  lymphatics,  held  them  only  as 
organs  of  circulation  for  restoring  to  the  heart  the  serum  of  the  blood.  The 
sagacious  mind  of  Dr.  W.  Hunter  first  imagined  their  absorbing  powers,  and 
established  the  theory  of  their  identity  of  function,  in  this  respect,  with  the 
lacteals.  The  priority  of  the  theory  was  warmly  contested  for  Dr.  Monro,  of 
Edinburgh. 

Vol.  II.— 28 


318 


ABSORBENT  SYSTEM. 


Of  the  Lymphatic  Glands. 

The  Lymphatic  or  Absorbent  Glands  or  Ganglions,  sometimes 
called  waxen  kernels  in  common  language,  are  an  appendage  of  a 
very  important  description  to  the  absorbent  system.  They  are  flat- 
tened ovoidal  bodies,  of  a reddish  ash  colour,  indurated  so  as  to  af- 
ford a strong  resistance  to  pressure,  and  of  a variable  volume,  from 
a line  to  twelve  lines  in  their  long  diameter.  They  are  found  prin- 
cipally in  clusters  or  chains,  and  are  more  abundant  in  the  neck,  in 
tire  groin,  in  the  arm-pit,  in  the  mesentery,  and  about  the  bifurcation 
of  the  trachea. 

The  lymphatic  vessels,  in  their  course  towards  the  thoracic  duct, 
have  to  pass  through  one  or  more  of  these  glands.  This  rule  is 
almost  universal ; some  exceptions,  however,  to  it,  in  the  case  of  the 
lower  extremities,  have  been  stated  by  Mr.  Hewson,  and  in  the 
case  of  the  back,  by  Mr.  Cruikshank  :*  the  latter  believes  Mr.  H.  to 
have  been  under  a misapprehension  in  this  statement  concerning  the 
extremities,  as  it  had  not  been  verified  by  the  result  of  his  own  in- 
vestigations. The  vessels  mat  enter  into  the  glands  are  called  vasa 
inferentia,  while  those  that  depart  from  them  are  the  vasa  efferentia. 
As,  owing  to  the  juxtaposition  of  many  of  these  glands,  the  vessels 
between  them  are  very  short,  this  distinction  would  likewise  seem 
almost  superfluous,  because  there  is  scarcely  space  to  apply  the  term 
efferentia,  before  the  same  vessels  enter  the  consecutive  gland,  thereby 
becoming  inferentia.  For  the  most  part,  the  vasa  inferentia  are 
more  numerous  and  somewhat  smaller  than  the  efferentia.  The 
former,  as  they  enter  the  gland,  radiate  into  smaller  branches,  while 
the  latter  are  formed  from  the  junction  of  smaller  branches. 

Each  lymphatic  gland  is  surrounded  by  a capsule,  resembling- 
condensed  cellular  substance,  which  adheres  very  closely  to  the 
gland,  and  from  which  cause  many  anatomists  are  disposed  to  deny 
its  existence,  at  least  as  a distinct  membrane.  They  are  also  abun- 
dantly furnished  with  arteries  and  with  veins  destitute  of  valves  ; 
but  though  they  are  penetrated  by  nervous  filaments,  it  is  not  yet 
satisfactorily  ascertained  that  any  remain  with  them  ; it  is,  however, 
more  probable  than  otherwise.  Their  connexion  with  the  surround^ 

* Anat.  of  Absorb.  Vessels,  second  edit.  p.  79.  London,  1790. 


LYMPHATIC  GLANDS. 


319 


ing  cellular  substance  is  sufficiently  loose  to  permit  them,  in  certain 
parts,  to  be  slid  moderately  backwards  and  forwards.  When  this 
motion  is  arrested,  it  is  from  inflammation  about  them. 

The  capsule  of  the  lymphatic  gland,  like  that  of  other  glands, 
sends  processes  within  to  keep  its  parts  together,  and  to  conduct  the 
blood  vessels.  It  also  contains  a peculiar  fluid  called,  by  Haller, 
succus  proprius,  which  is  principally  found  in  young  animals,  di-. 
minishes  as  they  advance  in  age,  and  finally  disappears.  It  is  of 
various  colours,  but  more  frequently  white  ; it  appears  to  have  globu- 
lar particles  in  it,  which  (he  late  Mr.  Hewson,  for  divers  reasons, 
thought  to  become  afterwards  the  red  globules  of  blood. 

When  a lymphatic  gland  is  injected  with  quicksilver,  it  appears 
to  be  made  up  by  the  minute  branching  of  the  vasa  inferentia,  and 
the  roots  of  the  vasa  efferentia,  the  former  being  continued  into  the 
latter.  There  is  also  some  appearance  of  small  cells  intermediate 
to  these  two  orders  of  vessels.  All  anatomists  admit  the  former 
opinion ; but  many  reject  the  latter,  under  a presumption  that  the 
appearance  is  delusive.  The  arguments  seem  to  be  in  favour  of 
their  existence.  Mr.  Cruikshank,*  whose  address  in  these  matters 
was  certainly  of  the  first  order,  declares  that  he  never  failed  to  per- 
ceive them,  and  particularly  well,  just  as  the  mercury  was  entering 
the  gland.  This  arrangement  is  still  more  readily  made  out  in  ani- 
mals, as  the  horse,  ass,  mule.  It  also  seems,  from  his  observations, 
that  when  there  are  more  than  one  vas  inferens  and  efferens,  there  are 
cells  for  each  set,  which  are  kept  distinct  from  the  cells  of  the  others, 
though  they  communicate  freely  with  their  cognates.  Mr.  Aber- 
nethy’s  investigations,  on  the  mesenteric  glands  of  whales,  coincide 
with  the  views  of  Mr.  Cruikshank : he  states,  indeed,  the  cells  as 
being  large  spherical  bags,  into  which  the  lacteals  plainly  open. 
The  celebrated  Mascagni  also  acknowledges,  and,  in  fact,  describes 
the  cellular  structure  of  these  glands, f which  he  had  ascertained 
both  by  quicksilver  and  by  wax  injections.  The  improved  notions 
of  modern  anatomy,  upon  what  is  called  the  erectile  tissue,  that  is, 
the  cells  intermediate  to  arteries  and  veins,  as  in  the  penis  and 
other  places,  and  now  considered  rather  as  the  dilated  extremities 
of  vessels,  would  also  assist  in  warranting  the  opinion  advocated. 
The  celebrated  Ruysch  thought  that  he  had  discovered  acini  in  the 
lymphatic  glands,  and  sent  his  injected  preparations  illustrative  of 


# Loc  cit.  p.  15,  pi.  iii. 


f Vasor.  Lymph.  HisL 


320 


ABSORBENT  SYSTEM. 


them  to  Boerhaave.  Some  idea  of  the  enthusiasm  of  the  anatomists 
of  old  may  be  conceived  by  his  saying  “ Quando  jam  clarius  et  per- 
fect ius  videbam  hrec  omnia,  prse  gaudio  exsiliebam.” 


When  the  absorbing  powers  of  the  lymphatics  had  been  esta- 
blished by  Dr.  W.  Hunter,  they  were  for  a long  time  considered  as 
the  exclusive  functionaries  in  this  operation;  and  the  opinions  pre- 
viously entertained  had  sunk  into  such  disrepute,  from  some  expe- 
riments of  Mr.  John  Hunter,* * * §  that  they  were  considered  rather  as 
food  for  literary  research  and  curiosity,  than  for  deliberate  adoption. 
In  the  year  1809,  M.  Magendie  reported  his  experiments  on  absorp- 
tion, which  seemed  to  favour  the  notion  that  the  veins  also  assisted 
in  this  office,  a theory  as  ancient  as  Galen.  The  more  recent  ob- 
servations of  Fohman,  in  1821,  and  Lauth,  in  1824,  on  the  com- 
munications of  the  lymphatics  with  the  veins,  in  the  midst  of  the 
tissues  of  organs,  and  in  the  lymphatic  glands,  seem  now  to  explain 
away  again  the  theories  of  the  absorbing  powers  of  the  veins,  and 
to  reinstate  the  lymphatics  in  their  reputed  exclusive  functions.  It 
is  also  stated  that  an  anatomist  of  Florence,  M.  Lippi,  has  still  more 
lately  found  several  large  lymphatic  trunks  entering  into  the  ascend- 
ing cava.  The  connexion  of  the  lymphatic  system  with  the  vena 
cava  ascendens,  and  also  with  the  external  iliac  veins  has  been 
farther  demonstrated  by  certain  preparations,  exhibited  by  M. 
Amussat  to  the  Academic  Royale.f  M.  Fodera  has,  however, 
again  brought  the  subject  under  discussion,  by  multiplying  the 
active  agents  of  this  function,  and  says,  that  his  experiments  prove 
that  all  organized  tissues  enjoy  it,  and  not  certain  parts  only,  as  has 
been  heretofore  supposed  from  which  it  results  that  most  of  the 
rules  in  regard  to  the  application  of  local  remedies  are  inexact,  and 
that  we  should  have  more  regard  to  the  thickness  and  density  of 
tissues,  to  the  quantity  and  rapidity  of  their  circulation,  than  to 
simple  locality. § 

* Med.  Commentaries. 

f Am.  Med.  Jour.  vol.  i.  p.  422. 

£ Reclierclies  Experimentales  sur  1 ’Absorption  et  l’Exhalation.  Paris, 
1824. 

§ For  a most  interesting  and  instructive  series  of  experiments  on  the  laws 
and  phenomena  of  absorption,  see  Philadelphia  Journal  of  the  Medical  and 
Physical  Sciences.  Nos.  6 and  10.  The  experiments  were  executed  by  Drs. 
Lawrence,  13.  H.  Coates,  and  Richard  Harlan,  of  this  city. 


ABSORBENTS  OF  THE  HEAD  AND  NECK. 


321 


CHAPTER  VI. 

Of  the  Special  Anatomy  of  the  Absorbent  System. 

SECT.  I. — OF  THE  ABSORBENTS  OF  THE  HEAD  AND  NECK. 

The  Superficial  Absorbents  of  the  head  are  found  in  company 
with  the  several  branches  of  the  temporal,  the  occipital,  the  frontal, 
and  the  facial  arteries,  and,  in  order  to  get  into  the  lymphatic  trunks 
leading  to  the  thoracic  duct,  follow  or  rather  reverse  the  course  of 
their  respective  arteries.  There  are  at  least  two  absorbent  trunks 
for  one  arterial,  and  frequently  more : those  on  the  face  are  more 
abundant  than  such  as  are  on  the  side  of  the  cranium,  owing  to  the 
excess  of  cellular  substance  on  the  former.  The  absorbents  of  these 
two  regions  anastomose  freely  beneath  the  external  ear,  between 
the  skin  and  the  parotid  gland. 

The  Deep-Seated  Absorbents  of  the  head  have  been  followed  to 
the  membranes  of  the  brain,  but  not  farther.  Ruysch  observed 
them  between  the  tunica  arachnoidea  and  the  pia  mater,  inflated 
with  air,  and  called  them  vasa  pseudo-lymphatica.  Lancisius, 
Pacchioni,  and  others,  assert  their  having  found  them  in  the  pia 
mater.  Doubts  are  cast  upon  these  several  observations,  owing  to 
such  vessels  not  having  been  injected  with  quicksilver,  and  from 
the  want  of  a valvular  appearance  in  them ; also  from  the  want  of 
lymphatic  glands  in  the  cavity  for  the  brain.  Their  existence, 
would  seem  to  be  sufficiently  proved,  both  from  general  analogy, 
and  from  affections  of  the  brain  producing  swellings  in  the  glands 
of  the  neck.  On  the  dura  mater  they  have  been  traced  along  the 
course  of  its  arteries.  They  descend  from  the  interior  of  the  cranium 
into  the  neck,  along  the  carolid  and  vertebral  arteries.  The  absence 
of  lymphatic  glands  in  the  cranium  may  be  accounted  for  from  the 
fact,  that  the  ready  tendency  of  these  organs  to  swell  upon  slight 
causes  of  irritation,  would  have  rendered  the  individual  liable  to 
death,  from  compression  of  the  brain,  by  their  tumefaction.  Mr. 
Cruikshank  considers  himself  to  have  found  lymphatic  glands  in  ths' 
carotid  canal. 


28* 


322 


ABSORBENT  SYSTEM. 


The  Deep  Lymphatics  of  the  face,  as  those  from  the  interior  of 
the  nose,  of  the  orbit,  of  the  tongue  and  mouth,  attend  the  arteries 
which  respectively  supply  those  parts. 

These  several  absorbents,  from  the  surface  and  from  the  interior 
of  the  head,  descend  to  the  base  of  the  cranium,  and  then  begin  to 
pass  through  the  chain  of  lymphatic  glands  situated  along  the  course 
of  the  great  blood  vessels  of  the  neck.  They  lie,  for  the  most  part, 
under  the  sterno- mastoid  muscle,  and,  when  successfully  injected, 
are  thought  to  form  the  most  brilliant  plexus  of  absorbents  in  the 
whole  frame.  On  each  side  of  the  neck,  one  or  more  common 
trunks  are,  at  length,  formed;  that  on  the  left  side  joins  the  Left 
Thoracic  Duct  near  its  termination,  while  the  one  on  the  right  assists 
in  forming  the  duct  peculiar  to  that  side,  the  Right  Thoracic  Duct, 
or,  more  properly  called,  the  right  Brachio  Cephalic. 

The  lymphatic  vessels  of  the  muscles  of  the  neck,  and  those  of  the 
thyroid  gland,  enter  into  the  trunks  of  the  neck.  According  to  Mr. 
Cruikshank,  those  of  the  thyroid  gland  may  be  readily  injected  by 
plunging  a lancet  at  random  into  its  substance,  and  then  introducing 
air  or  quicksilver. 

Of  the  Absorbent  Glands  of  the  Head  and  JYeck. 

The  only  claim  of  lymphatic  glands  to  an  existence  in  the  cavity 
of  the  cranium,  is  founded  upon  the  supposition  that  the  Pineal,  the 
Pituitary,  and  Pacchioni’s  Glands  are  of  this  character;  but  it  is  far 
from  being  established,  and  there  seems  indeed  to  be  some  doubt 
whether  the  glands  found  in  the  carotid  canal,  by  Mr.  Cruikshank, 
are  not  the  carotid  ganglion  of  the  Sympathetic,  noticed  by  Lau- 
monier. 

On  the  external  surface  of  the  cranium,  over  the  insertion  of  the 
sterno-mastoid  muscle,  there  are  from  four  to  six  of  a small  volume ; 
on  the  face  there  is  one  or  more  small  ones,  below  the  zygoma,  and 
from  two  to  four  on  the  external  surface  of  the  parotid ; there  is  one 
or  more  small  ones  situated  in  the  substance  of  the  parotid  gland, 
which  according  to  Burns,  are  generally  the  seat  of  tumours  falsely 
attributed  to  the  parotid  itself.  There  are  also  some  small  glands 
along  the  facial  artery  as  it  ascends  from  the  base  of  the  jaw  to  the 
corner  of  the  mouth. 

On  the  neck  there  are  two  or  more  small  glands,  immediately, 


ABSORBENTS  OF  THE  HEAD  AND  NECK. 


323 


under  the  skin  of  the  symphysis  of  the  jaw,  and  eight  or  nine  around 
the  submaxillary  gland.  The  most  numerous  congeries  of  glands 
on  the  neck  is,  along  its  great  blood  vessels,  and  covered  more  or 
less  by  the  sterno-mastoid  muscle,  being  principally  between  its 
posterior  margin  and  the  anterior  of  the  trapezius.  Along  the  latter 
line  there  are  about  twenty,  in  addition  to  six  just  above  the  superior 
margin  of  the  clavicle.  On  the  trachea,  just  above  the  sternum, 
there  are  four,  forming  the  upper  end  of  a series  which  descends 
along  the  oesophagus  and  trachea  to  the  root  of  the  lungs. 

SECT.  II. — OF  THE  ABSORBENTS  OF  THE  UPPER  EXTREMITIES 
AND  OF  THE  CONTIGUOUS  PARTS  OF  THE  TRUNK  OF  THE 
BODY.'*' 


The  superficial  absorbents  of  the  upper  extremities  are  very  nu- 
merous, and  lie  between  the  skin  and  aponeurosis.  They  begin  at 
the  ends  of  the  fingers  and  thumb;  there  being  two  or  more  branches 
for  each,  both  before  and  behind.  The  posterior  branches  pass  to 
the  back  of  the  hand  and  of  the  fore-arm : some  of  them,  more  espe- 
cially those  from  about  the  thumb,  run  up  along  the  radial  side  of 
the  fore-arm  to  the  bend  of  the  arm ; but  by  far  the  greater  part  of 
them  incline  very  gradually  in  a semi-spiral  manner  towards  the 
ulna,  and  then  to  the  front  of  the  fore-arm. 

Such  of  the  superficial  vessels  as  come  from  the  front  of  the  fin- 
gers and  hand,  continue  to  ascend  straight  up  the  fore-arm  to  its 
bend.  These  vessels  of  the  fore-arm  are  so  numerous  that  for  every 
few  lines  there  is  an  ascending  trunk  on  its  circumference  : some  of 
them  coalesce,  others  form  plexuses,  and  their  number  is  much  re- 
duced at  the  elbow. 

From  the  elbow  the  superficial  lymphatics  ascend  to  the  axilla  in 
fifteen  or  twenty  parallel  trunks,  along  the  internal  margin  and  the 
front  surface  of  the  biceps  flexor  cubiti.  The  outer  side  of  the  arm 
has  comparatively  but  few  absorbent  trunks  upon  it,  but  some  follow 
the  course  of  the  cephalic  vein,  penetrate  with  it  into  the  axilla,  and, 
then  join  the  inferior  lymphatics  of  the  neck. 

The  Deep  Absorbents  of  the  upper  extremity  attend  the  arteries.. 


* Anat.  Atlas,  Figs.  498, 499., 


324 


ABSORBENT  SYSTEM. 


and  are  at  least  two  for  each  principal  artery.  They  anastomose 
with  the  superficial  ones  at  intervals,  and  at  last  terminate  in  the 
axillary  glands.  As  they  follow  strictly  the  course  of  the-  arteries, 
a farther  specification  is  needless. 

The  Superficial  Absorbents  of  the  contiguous  portions  of  the  trunk 
of  the  body  are  not  by  any  means  so  numerous  as  those  of  the  upper 
extremity  ; they  consequently  are  more  distant  from  one  another, 
and  they  also  go  along  in  a more  serpentine  manner.  From  the 
nape  of  the  neck  to  the  lower  part  of  the  loins  they  all  converge  to 
tire  arm-pit.  The  absorbents  which  are  situated  on  the  front  of  the 
pectoralis  major  muscle,  and  those  on  the  side  of  the  body  from  the 
arm-pit  to  the  hip,  also  converge  to  the  axilla.  In  regard  to  the 
two  latter  places,  some  of  their  absorbents,  by  penetrating  the  pa- 
rietes  of  the  thorax  or  abdomen,  respectively  join  the  internal  ab- 
sorbent trunk  of  thes£  cavities. 

These  several  lymphatics  from  the  upper  extremity  and  from  the 
trunk,  traverse  the  axillary  glands,  and  are  successively  reduced  in 
number  to  four  or  five  voluminous  trunks,  which'  surround  the  sub- 
clavian artery.  While  in  the  axilla  they  are  re-enforced  by  the  deep 
lymphatics  from  beneath  the  pectoralis  major,  the  latissimus  dorsi, 
and  the  shoulder.  Their  number  being  again  reduced,  they  go  along 
the  subclavian  vein  over  the  first  rib ; those  of  the  left  side  open  either 
into  the  thoracic  duct  at  its  termination,  or  into  the  subclavian  vein, 
near  it : but  those  on  the  right  are  finally  assembled  into  the  single 
large  trunk,  brachio-cephalic,  which  discharges  into  the  angle  of 
junction  of  the  right  internal  jugular  and  subclavian  vein. 

Absorbent  Glands  of  the  Upper  Extremity. 

These  glands  are  rarely  found  on  the  fore-arm,  but  when  they  do 
exist,  it  is  in  the  course  of  the  deep  absorbents,  and  they  are  very 
small,  and  but  few.  From  one  to  four  are  found  scattered  on  the 
front  of  the  elbow  and  internal  condyle.  From  four  to  seven  exist 
along  the  sheath  of  the  brachial  vessels  and  nerves. 

The  axillary  glands  are  very  numerous,  and  of  different  sizes; 
they  are  dispersed  throughout  the  cellular  substance  of  the.  axilla, 
reposing  on  the  serratus  major  anticus,  between  the  pectoral  muscles 
and  those  of  the  shoulder,  and  being  for  the  most  part,  below  the 


ABSORBENTS  OF  THE  INFERIOR  EXTREMITIES, 


325 


axillary  vessels  and  nerves,  but  some  reposing  immediately  upon 
them,  and  forming  a chain  from  the  lower  part  of  the  axilla  to  the 
clavicle.  Their  number  is  from  fifteen  to  thirty-five  or  forty.  All 
the  absorbents  which  observe  the  route  of  the  axilla  to  reach  the 
thoracic  duct  have  to  pass  through  these  glands. 


SECT.  III. — ABSORBENTS  OF  THE  INFERIOR  EXTREMITIES, 

AND  OF  THE  CONTIGUOUS  PARTS  OF  THE  TRUNK  OF  THE 

BODY.* 

The  superficial  absorbents,  like  those  of  the  upper  extremities, 
are  placed  between  the  skin  and  the  aponeurosis,  in  the  cellular 
tissue  that  contains  the  subcutaneous  veins.  They  are  also  very 
abundant,  and  are  found  every  few  lines  on  the' circumference  of  the 
limb  ; they  are,  however,  more  numerous  internally  than  externally, 
and,  for  the  most  part,  run  upwards. 

Those  on  the  inner  or  anterior  side  of  the  limb  are  first  perceived 
on  the  back  of  the  toes  and  foot.  They  incline  aver  the  front  of  the 
ankle,  and  its  internal  face,  to  the  inner  side  of  the  leg;  they  then 
ascend  over  the  inner  side  of  the  knee,  and  along  the  same  side  of 
the  thigh  to  the  groin.  The  superficial  absorbents  of  the  back  of 
the  lower  extremity  are  first  perceived  on  the  sole  of  the  foot.  They 
ascend  along  the  back  of  the  outer  ankle  and  of  the  leg  above  the 
knee ; they  then  incline  semi-spirally  inwards,  so  as  to  bring  them- 
selves to  the  front  of  the  thigh.  These  several  absorbents,  though 
there  are  but  few  on  the  foot,  augment  continually  in  number  by 
new  accessions  in  their  ascent.  All  those  on  the  posterior  internal 
face  of  the  thigh  wind  over  its  internal  side,  while  such  as  are  on  its 
posterior  external  face  wind  over  the  outer  side,  to  reach  the  in- 
guinal glands. 

The  Deep  Absorbents  adhere  to  the  arteries,  being  at  least  two 
to  each,  and  adopting  the  same  distribution  and  nomenclature. 
The  anterior  tibial  set  begins  in  the  sole  of  the  foot,  and  rises  to  its 
back  between  the  first  two  metatarsal  bones ; another  branch  begins 


* Anat.  Atlas,  Figs.  503  to  507,  inclusive. 


326 


ABSORBENT  SYSTEM. 


on  the  dorsum  of  the  foot.  The  first  pursues  the  course  of  the  an- 
terior tibial  artery  through  the  interosseal  ligament  to  the  ham,  the 
second  frequently  joins  the  peroneal  absorbents  about  half  way  up 
the  leg.  The  posterior  tibial  and  the  peroneal  absorbents,  as  they 
cruise  along  their  respective  arteries,  do  not  require  any  farther  com- 
ment. There  is  a fourth  set  of  these  deep  absorbents,  amounting  to 
two  or  three  in  number,  which  attend  the  external  saphena  vein,  and 
come  from  the  external  side  of  the  foot.  Getting  between  the  heads 
of  the  gastrocnemii  muscles,  they  are  re-enforced  by  other  trunks 
from  this  muscle ; some  of  the  branches  then  associate  themselves 
with  the  superficial  lymphatics,  and  others  penetrate  the  ham,  so  as 
to  join  the  deep  trunks  there. 

The  deep  absorbents  of  the  leg  coalesce  partially  in  the  ham,  and 
ascend  along  the  popliteal  artery.  On  the  thigh,  there  are  from  four 
to  eight  of  these  trunks  attending  the  femoral  artery,  and  receiving 
additions  as  the  latter  detaches  branches. 

There  are  two  or  three  lymphatic  vessels  on  each  side  of  the 
penis,  which  begin  at  its  glans  and  prepuce,  and  traversing  the 
length  of  this  organ,  wind  above  the  external  abdominal  ring  to  join 
tire  nearest  inguinal  gland.  There  are  several  from  the  side  of  the 
scrotum  and  perineum,  which  ascend  along  the  chord  and  thigh  to 
join  also  the  nearest  inguinal  gland.  In  the  female,  those  of  the 
labia  externa  and  clitoris  correspond  with  those  of  the  scrotum  and 
penis. 

The  superficial  absorbent  trunks,  from  the  lower  front  of  the  ab- 
domen, are  not  numerous  ; they  descend  and  converge  also  to  the 
inguinal  glands.  Some  of  those  from  the  loins,  such  as  do  not  as- 
cend to  the  axilla,  advance  to  the  inguinal  glands.  Those  of  the 
buttocks  do  the  same. 

Absorbent  Glands  of  the  Lower  Extremities 

Absorbent  Glands,  below  the  knee,  are  not  abundant,  or  indeed, 
veiy  common ; yet,  one  or  two  exist  sometimes  in  the  course  of  the 
anterior  tibial  artery  in  the  upper  part  of  the  leg.  The  popliteal 
glands  are  three  or  four;  they  are  small,  and  scattered  at  wide  inter- 
vals in  the  fat  of  the  ham  around  its  vessels.  From  the  latter  to  th$ 
groin,  they  are  not  usually  found  at  all. 

The  Inguinal  Glands  are  amongst  the  largest  in  the  system ; they 


DEEP  ABSORBENTS  OF  THE  PELVIS. 


327 


repose  along  the  anterior  margin  of  Poupart’s  ligament  and  a little 
below,  and  are  readily  felt  beneath  the  skin.  The  superficial  vary 
in  number,  in  different  individuals,  from  seven  to  twenty,  being 
more  numerous  as  they  are  smaller,  and  are  placed  between  the  la- 
minae of  the  fascia  superficialis.  They  receive  first  of  all,  the  super- 
ficial lymphatics  of  all  the  parts  mentioned.  The  deep-seated  are 
smaller,  are  a little  lower  down  on  the  thigh,  and  lie  along  the  course 
of  the  femoral  artery,  beneath  the  aponeurosis  of  the  thigh ; they  are 
from  three  to  seven  in  number,  but  are  much  less  constant  than  the 
superficial. 

SECT.  IV. — DEEP  ABSORBENTS  OF  THE  PELVIS.* 

The  Deep  Absorbents  of  the  parietes  of  the  pelvis,  as  in  other 
cases,  attend  the  arteries  of  the  part  and  have  the  same  names.  The 
obturators  come  from  the  heads  of  the  adductor  muscles,  and  pass- 
ing through  the  obturator  foramen,  end  in  the  hypogastric  glands. 
The  ischiatics  come  from  the  small  muscles  on  the  back  of  the  hip 
joint,  and  getting  into  the  pelvis  along  with  the  ischiatic  artery,  they 
also  terminate  in  the  hypogastric  glands.  The  gluteals  come  from 
the  three  gluteal  muscles,  and  entering  the  pelvis  along  with  the 
artery  at  the  superior  margin  of  the  sciatic  notch,  they  likewise  ter- 
minate in  the  hypogastric  glands  along  with  some  vessels  from  the 
anus  and  the  perineum.  The  ileo-lumbar,  the  sacral,  and  the  cir- 
cumflex iliac  absorbents,  also  follow  their  respective  arteries  and 
terminate  in  the  nearest  glands. 

The  absorbents  of  the  Testicle  are  numerous  and  large:  accord- 
ing to  Dr.  W.  Hunter,!  they  can  sometimes  be  very  completely 
injected  by  a pipe  thrust  into  the  substance  of  the  testicle,  and, 
according  to  Cruikshank,j:  very  advantageously  from  the  vas  defe- 
rens, which  has  succeeded  in  my  own  hands.  They  form  two 
layers,  one  superficial  coming  from  the  tunica  vaginalis  testis,  and 
the  other  from  the  substance  of  the  gland.  They,  finally  unite,  into 
some  six  or  eight  trunks,  which§  ascend  with  the  chord  through  the 
abdominal  canal.  Occasionally  one  or  more  of  them  is  as  large  as 
a crow-quill.  By  following  the  course  of  the  spermatic  artery,  they 
at  last  terminate  in  the  lumbar  glands. 


* Anat.  Atlas,  Fig.  500. 
f Loc.  cit.  p.  155. 


f Loc.  cit. 

§ Mascagni,  loc.  cit. 


32S 


ABSORBENT  SYSTEM. 


The  deep  absorbents  of  the  Penis  accompany  the  arteries,  and, 
therefore,  either  get  into  the  pelvis  beneath  the  symphysis  of  the 
pubes,  or  along  the  crura  and  the  tuberosities  of  the  ischia  ; hence, 
a chancre  on  the  prepuce  causes  bubo,  while  one  on  the  glans  very 
rarely  does,  and  yet  the  constitution  will  be  equally  affected.* 
These  absorbents  terminate  in  the  hypogastric  glands. 

The  deep  absorbents  of  the  Clitoris  follow,  in  the  same  way,  the 
internal  pudic  artery. 

The  absorbents  of  the  Urinary  Bladder  are  also  numerous,  and 
pass  in  several  trunks  from  its  sides  to  the  hypogastric  glands. 
Those  of  the  prostate  gland  and  vesicular  seminales  are  associated 
with  them. 

The  absorbents  of  the  lower  part  of  the  vagina  accompany  the 
round  ligament  of  the  uterus  through  the  abdominal  canal,  and, 
finally  anastomose  with  those  of  the  uterus.  Those  of  the  upper 
portion  of  the  vagina  are  immediately  associated  with  such  as  be- 
long to  the  uterus. 

The  absorbents  of  the  uterus  are  not  so  well  seen  in  the  unim- 
pregnated state,  but  in  impregnation  they  are  so  prodigiously  nume- 
rous that  when  injected  with  quicksilver,  one  is  almost  tempted  to 
suppose  that  the  uterus  consists  entirely  of  them.  Mascagni’s  plate 
on  this  subject  is  an  exquisite  specimen.!  As  they  all  terminate  in 
the  hypogastric  trunks,  the  latter  are  in  such  case  as  large  as  goose- 
quills.:]: 

The  hypogastric  plexus,  from  these  several  accessions  from  the 
parietes  and  viscera  of  the  pelvis,  becomes  very  large,  and  follows 
the  course  of  the  hypogastric  artery  in  ascending  into  the  loins. 

There  are  likewise  some  spermatic  absorbents  in  the  female, 
called  so  from  attending  the  vessels  of  the  same  name.  They  come 
from  the  ovarium,  the  Fallopian  tube,  and  the  round  ligament,  to 
terminate  in  the  lumbar  glands  : they  anastomose  below  with  those 
of  the  uterus. 


Of  the  Glands  of  the  Pelvis. 

Some  few  glands  lie  beneath  the  gluteus  magnus  muscle,  but 
the  majority  are  within  the  pelvis.  Those  which  are  called  the  Ex- 
ternal Iliac  are  at  least  six,  frequently  more,  and  extend  from  Pou- 


* Cruikshank,  loc.  cit.  f Loc.  cit.  % Cruikshank,  loc.  cit. 


ABSORBENTS  OF  THE  ORGANS  OF  DIGESTION. 


329 


part’s  Ligament  to  the  lower  part  of  the  loins,  being  planted  along 
the  external  iliac  artery,  both  above  and  below.  The  Hypogastric 
or  Internal  Iliac  Glands  are  rather  more  numerous  than  the  others, 
and  form  a chain  along  the  hypogastric  artery.  They  are  much 
disposed  to  form  large  indurated  masses  from  diseases  of  the  rec- 
tum, uterus,  and  bladder.* 

SECT.  V. — ABSORBENTS  OF  THE  ORGANS  OF  DIGESTION,  f 

The  Absorbents  of  the  Stomach  are  very  numerous,  and  lie  in 
two  planes:  one  is  superficial,  being  immediately  beneath  the  peri- 
toneal coat,  and  the  other  is  profound  being  placed  between  the 
muscular  and  the  mucous  coat.  They  are,  finally,  assembled  into 
three  divisions,  which  follow  the  course  of  the  principal  blood  ves- 
sels of  this  organ. 

One  division  coming  from  the  anterior  and  the  posterior  face  of 
the  stomach,  converges  to  its  lesser  curvature,  and  passes  through 
some  six  or  eight  small  glands  in  the  adjacent  portion  of  the  lesser 
omentum.  Inclining  to  the  right  of  the  cardiac  orifice,  its  trunks 
then  pass  through  some  glands  common  to  them  and  to  the  deep 
lymphatics  of  the  liver.  Their  numbers  being  reduced,  they  then 
descend  behind  the  pancreas,  and  terminate  in  the  thoracic  duct 
near  the  cceliac  artery. 

The  second  division  comes  from  the  left  inferior  portion  of  the 
stomach,  and  from  its  greater  extremity,  and,  blending  with  the  ab- 
sorbents of  the  spleen  and  pancreas,  goes  with  them  into  the  tho- 
racic duct. 

The  third  division  comes  from  the  right  inferior  portion  of  the 
stomach,  and,  assembling  towards  the  pylorus,  is  subsequently 
mixed  with  some  of  the  absorbents  of  the  liver  and  of  the  small  in- 
testines, and  goes  along  with  them  into  the  thoracic  duct. 

The  Absorbents  of  the  Great  Omentum  join  those  of  the  stomach 
and  of  the  colon,  at  the  points  most  -convenient  to  them. 

The  Absorbents  of  the  Small  Intestines,,  like  those  of  the  stomach, 
are  both  superficial  and  deep,  and  from  the  function  of  conveying 

* Cruikshank,  loc.  cit,  Ij-  Anat.  Atlas,  Figs.  501,  505. 

Vol.  II.— 29 


330 


ABSORBENT  SYSTEM. 


chyle,  have  been  called  lacteals,  or  chyliferous  vessels.  As  the 
chyle,  however,  can  only  be  absorbed  by  the  deep  ones : as  they 
and  the  superficial  have  common  trunks,  and  as  they  also  absorb, 
from  the  intestines,  fluids  not  converted  into  chyle  ; there  seems  to 
be  no  necessity  for  distinguishing  them  by  a particular  epithet.  The 
deep  are  in  the  cellular  coat  of  the  intestine,  and  follow  the  ramifi- 
cations of  the  arteries,  being  double  their  number.  The  superficial, 
being  immediately  beneath  the  peritoneal  coat,  run  for  some  distance, 
longitudinally,  on  the  gut,  and  then  turn  off  to  the  mesentery  at  right 
angles. 

On  the  mesentery  these  absorbents  are  not  rigidly  bound  to  the 
course  of  the  blood  vessels ; they  converge  in  a slightly  tortuous 
manner  from  its  circumference  to  its  root.  They  anastomose  with 
one  another,  by  which  their  number  is  reduced;  and  they  also  have 
to  pass  through  the  series  of  mesenteric  glands.  The  lacteals  of  the 
duodenum  and  jejunum  are  larger  and  more  numerous  than  those  of 
the  ileum,  in  the  proportion  of  the  greater  extent  of  the  internal  sur- 
face of  the  former  intestines,  from  the  number  of  their  valvulse  con- 
niventes.  The  vessels  of  the  mesentery,  after  having  cleared  the 
series  of  glands,  and  held  some  intercourse  with  the  lymphatics  of 
the  spleen,  liver,  stomach,  and  pancreas,  are  reduced  at  last  into 
one  or  more  large  trunks,  which,  observing  the  course  of  the  su- 
perior mesenteric  artery,  empty  near  the  root  of  the  latter,  but  some- 
times lower  down,  into  the  thoracic  duct. 

The  absorbents  of  the  Large  Intestines  are  much  less  numerous 
than  those  of  the  small.  They  are  also  superficial  and  deep,  and 
observe  the  course  of  the  blood  vessels.  Those  from  the  right  por- 
tion and  middle  of  the  colon  join  the  lacteals  of  the  mesentery, 
while  such  as  belong  to  the  sigmoid  flexure  follow  the  inferior  me- 
senteric artery  up  to  the  lumbar  glands.  Those  of  the  rectum  go 
partly  into  the  lumbar  and  partly  into  the  hypogastric  glands, 
and  as  its  blood  vessels  are  more  numerous  than  those  of  other 
portions  of  the  large  intestine,  its  absorbents  are  in  the  same  propor- 
tion.* 

The  Absorbents  of  the  Liver  are  exceedingly  numerous,  and  are 


* Cruikshank,  loc.  eit. 


ABSORBENTS  OF  THE  ORGANS  OF  DIGESTION. 


331 


also  injected  with  unusual  ease  from  the  larger  into  the  smaller 
trunks,  from  the  imperfection  of  the  valvular  arrangements.  They 
are  also  superficial  and  deep. 

The  Superficial  Absorbents  of  the  upper  surface  of  the  liver  run 
in  several  divisions,  the  number  of  which  is  unsettled.  Those  near 
the  middle  front  of  the  liver  assemble  into  six  or  more  trunks,  which 
ascend  the  suspensory  ligament,  and  enter  the  thorax  between  the 
diaphragm  and  the  sternum.  They  are  joined  by  several  trunks 
from  the  diaphragm,  and  continuing  to  ascend  up  the  anterior  me- 
diastinum between  its  laminae  behind  the  sternum,  they  are  re-en- 
forced by  contributions  from  the  pericardium,  from  the  thymus  gland, 
and  from  the  anterior  parietes  of  the  thorax.  The  division  then 
crosses  the  upper  end  of  the  descending  cava,  and  those  from  the 
two  sides  assembling,  they  go  in  one  or  more  large  trunks  along  the 
left  vena  innominata,  and  finally  empty  into  the  left  thoracic  duct 
near  its  termination.  Sometimes  they  enter  into  the  right  thoracic 
duct.  It  occasionally  happens  that  a detachment  of  this  division, 
instead  of  ascending  through  the  mediastinum,  is  directed  towards 
the  coronary  ligament  of  the  liver;  and  being  there  joined  by 
other  vessels,  it  enters  immediately  into  the  thoracic  duct  at  the 
upper  part  of  tire  abdominal  cavity,  or  at  the  lower  part  of  the 
thorax. 

Another  division  comes  from  the  upper  surface  of  the  right  lobe, 
and  gaining  the  right  lateral  ligament,  penetrates  into  the  thorax 
through  the  diaphragm,  and  advancing  along  the  costal  margin  of 
this  muscle,  terminates  in  the  first  division  under  the  sternum. 
Sometimes  one  of  its  branches,  thrice  as  large  as  a crow-quill,  runs 
backward  to  the  spine,  and  is  inserted  into  the  thoracic  duct  behind 
the  oesophagus,  without  passing  through  any  gland;  there  are  also, 
occasionally,  several  other  arrangements  of  the  trunks  of  this  di- 
vision.* 

Another  division  comes  from  the  upper  surface  of  the  left  lobe  of 
the  liver ; and  its  trunks  advancing  to  the  left  lateral  ligament,  get 
into  the  thorax  through  the  diaphragm.  Some  of  the  trunks  then 
run  forward  on  the  convexity  of  this  muscle,  to  terminate  in  the 
trunks  under  the  sternum,  while  others  retire  backward  to  end  in 


* Cruikshank,  loc.  cit. 


332 


ABSORBENT  SYSTEM. 


the  glands  around  the  oesophagus,  immediately  above  the  dia- 
phragm. 

There  are  various  departures  from  this  general  arrangement  of  the 
absorbents  on  the  upper  surface  of  the  liver;  as  their  trunks  invari- 
ably reach  the  thoracic  duct  ultimately,  the  particular  routes  do  not 
seem  to  be  rigidly  fixed. 

The  Superficial  Absorbents  of  the  under  surface  of  the  liver  pre- 
sent, also,  diversities,  but  they  are  seldom  arranged  into  so  many 
divisions  as  those  of  the  upper  surface.  They  communicate  freely 
with  the  latter,  and  also  with  the  profound,  and,  finally,  assembling 
in  the  transverse  fissure,  they  descend  along  the  capsule  of  Glisson 
to  join  and  anastomose  with  the  contiguous  trunks  from  the  alimen- 
tary canal,  from  the  pancreas,  and  from  the  spleen. 

The  Deep  Absorbents  of  the  liver  follow  the  branching  of  the  vena 
portarum,  and,  emerging  at  the  transverse  fissure,  pass  through  the 
glands  in  the  capsule  of  Glisson,  associating  themselves  at  the  same 
time  with  the  superficial  trunks,  and  having  a common  termination 
with  them.  By  putting  a ligature  around  the  vena  portarum  of  a 
living  animal,  many  of  them  are  included  in  it ; they  then  become 
exceedingly  turgid,  and  are  seen  to  diverge  through  the  liver  like 
the  pori  biliarii. 

The  liver  is  said  to  be  more  abundantly  furnished  with  absorbents 
than  any  other  viscus. 

The  Absorbents  of  the  Spleen  are  also  superficial  and  deep-seated. 
The  former  are  between  the  peritoneal  and  the  proper  coat,  and  are 
injected  with  some  difficulty  in  the  human  subject,  but  are  very 
demonstrable  and  numerous  in  the  calf.  The  latter  emerge  at  the 
fissure  of  the  spleen,  and,  traversing  the  glands  that  lie  along  the 
course  of  the  splenic  artery,  receive  successively  the  absorbents  from 
the  pancreas.  They,  finally,  end  in  the  thoracic  duct,  after  recipro- 
cal junctions,  and  anastomose  with  the  vessels  from  the  stomach  and 
liver. 

The  Absorbents  of  the  Pancreas  are  also  numerous,  and  may 
be  injected,  contrary  to  their  circulation,  from  those  of  the  liver. 
They  arise  from  the  substance  of  the  pancreas,  like  its.  vessels, 


ABSORBENTS  OF  THE  ABDOMEN. 


333 


by  short  trunks,  which  join  those  of  the  Splenic  Plexus  at  right 
angles. 

The  Absorbents  of  the  Kidneys  are  superficial  and  deep ; the 
former,  though  numerous,  are  too  small  in  the  healthy  state  of  these 
organs  to  be  well  seen,  but  they  become  very  distinct  from  disease, 
and  converge  from  its  periphery  to  its  fissure.  The  deep  absorbents 
accompany  the  vessels,  and,  emerging  with  them  at  the  fissure,  are 
joined  with  the  superficial;  they  all  then  run  along  the  emulgent 
vessels,  and  have  frequent  anastomoses  with  those  of  the  testicles  or 
ovaries,  and  with  those  of  the  capsulae  renales.  These  absorbents 
may  be  filled  by  putting  a pipe  into-  the  excretory  duct  of  the 
kidney. 

The  Absorbents  of  the  Capsulae  Renales  unite  to  those  from  the 
kidneys,  and,  therefore,  terminate  with  them  in  the  lumbar  glands 

Of  the  Absorbent  Glands  of  the  Abdomen. 

The  cavity  of  the  abdomen  contains  many  more  glands  that  any 
other  region  of  the  body,  on  account  of  the  very  great  extension  of 
the  serous  system  in  it;  of  the  functions  exercised  by  its  viscera;  and 
of  its  being  traversed  by  the  absorbents  of  the  lower  extremities. 
Many  of  these  Glands  have  already-  been  described  under  the  de- 
nomination of  hypogastric,  and  external  iliac  ; in  addition  to  which 
there  are  a few  between  the  laminae  of  the  meso-reetum  in  front  of 
the  sacrum. 

The  Mesenteric  Glands  are  exceedingly  numerous,  and  amount 
to  between  one  and  two  hundred ; they  begin  at  an  inch  or  two  from 
the  small  intestines,  and  may  be  traced  to  the  root  of  the  mesentery, 
being  placed  between  its  layers,  on  the  convex  side  of  the  upper 
mesenteric  artery.  As  the  intestinal  cartal  is  longer  in  some  indivi- 
duals than  in  others,  they  are  proportionately  more  numerous.  Their 
largest  size  seldom  exceeds  that  of  an  almond  : those  belonging  to 
the  jejunum  are  rather  more  developed  than  such  as  belong  to  the 
ilium,  and  they  all  augment  in  size  as  they  approach  the  root  of  the 
ipesentery. 

The  Glands  of  the  Mesocolon  are  placed  between  the  laminae  of 

29* 


334 


ABSORBENT  SYSTEM. 


this  membrane,  near  the  intestine ; they  receive  the  absorbents  from 
the  large  intestines,  are  much  smaller  than  those  of  the  mesentery, 
and  their  number  seldom  exceeds  fifty.  Some  few  of  them  are  situ- 
ated near  the  root  of  the  mesocolon.  They  are  by  no  means  so  dis- 
posed to  tumefaction  from  scrofulous  affections  as  those  of  the  Me- 
sentery. It  is  stated  by  Winslow,  that  lie  demonstrated  to  the 
Academy  of  Sciences  at  Paris,  chyle  in  the  absorbents  of  the  Meso- 
colon ; this  fact  will  assist  us  in  accounting  for  the  effects  of  nutritive 
clysters. 

The  Gastro-Epiploic  Glands  are  situated  between  the  laminae  of 
the  omenta,  where  they  join  the  curvatures  of  the  stomach.  Their 
number  seldom  exceeds  four  or  five  for  each  curvature,  and  they 
receive  the  absorbents  of  the  stomach  and  omenta. 

The  Coeliac  Glands  are  those  which  belong  to  the  liver,  the  spleen, 
and  the  pancreas ; they  follow  the  course  of  the  blood  vessels  of 
these  organs,  and  are  traversed  by  their  absorbents.  The  trunk  of 
the  vena  portarum  is  surrounded  by  them,  and  Mr.  Cruikshank  says, 
that  he  has  seen  the  biliary  and  pancreatic  ducts  in  a state  of  com- 
pression from  their  tumefaction. 

The  Lumbar  Glands  are  very  numerous  and  large ; they  are 
scattered  over  the  whole  region,  from  the  base  of  the  sacrum  to  the 
pillars  of  the  diaphragm,  lying  on  each  side  of  the  bodies  of  the 
lumbar  vertebrae,  and  in  front  of  the  abdominal  aorta  and  vena  cava, 
being  concealed  by  the  root  of  the  mesentery  and  of  the  mesocolon. 
They  may  be  considered  as  continuations  of  all  the  preceding  con- 
geries of  glands  in  the  abdomen,  and,  therefore,  when  they,  along 
with  the  vessels  leading  to  them,  are  successfully  injected,  they  form 
so  thick  a plexus  of  absorbents,  reaching  from  the  pelvis  to  the  con- 
cavity of  the  diaphragm,  that  the  great  blood  vessels  can  scarcely 
be  seen  for  them.  Many  of  the  vessels  reaching  from  one  to  another 
are  as  large  as  a crow-quill. 


SECT.  VI. — ABSORBENTS  OF  THE  VISCERA  OF  THE  THORAX. 

The  Absorbents  of  the  Lungs  are  thought  to  be  next  in  abundance 
after  those  of  the  liver,  and  are  likewise  divided  into  two  sets,  the 


ABSORBENTS  OF  THE  THORAX. 


335 


superficial  and  the  deep-seated.  The  former  are  beneath  the  pleura 
pulmonalis.  Mr.  Cruikshank*  says,  that  they  are  not  always  to  be 
found,  though  commonly  he  has  readily  shown  them  covering  with 
their  meshes  the  whole  external  surface  of  the  lung.  The  larger 
meshes  follow  the  interstices  of  the  lobules,  and  within  them  are 
others  of  extreme  delicacy.  The  same  author  states,  that  one  of  the 
easiest  methods  of  finding  them,  is  to  inflate  the  lungs  of  a still-born 
child,  from  the  trachea,  and  the  air  in  passing  from  its  proper  cells, 
will  get  into  the  absorbents;  a puncture  being  then  made  into  one 
of  the  latter,  quicksilver  may  be  very  readily  introduced.  Some  of 
their  trunks  penetrate  to  the  bottom  of  the  fissures  of  the  lungs,  and 
pass  through  the  glands  there,  while  others  continue  more  superficial 
along  the  internal  face  of  the  lung,  and  so  reach  the  bronchial  glands. 

The  deep  absorbents  of  the  lungs  observe  the  course  of  the  pul- 
monary vessels  and  of  the  bronchia.  They  arise  from  the  substance 
of  the  lung,  anastomose  very  freely  with  the  superficial  vessels,  and 
in  parting  from  the  lung,  pass  through  the  bronchial  glands,  where 
they  are  joined  by  the  superficial. 

By  the  junction  of  the  branches  from  the  left  lung,  three  consi- 
derable trunks  are  formed ; one,  which  is  sometimes  the  size  of  a 
goose-quill,  is  inserted  into  the  thoracic  duct,  immediately  behind 
the  bifurcation  of  the  trachea  ; another  ascends  between  the  trachea 
and  the  oesophagus,  to  join  the  thoracic  duct  near  its  termination; 
and  the  third  joins  the  glands  belonging  to  the  absorbents  of  the 
heart,  f 

The  absorbents  of  the  right  lung  also  coalesce  into  three  principal 
trunks  at  the  root  of  the  lung:  one  of  them  ascends  across  the  front 
of  the  superior  cava,  making,  in  its  course,  many  elegant  convolu- 
tions, and  at  length  terminates  in  the  second  trunk  on  the  left  side.j; 
The  other  trunks,  ascending  on  the  side  of  the  trachea,  and  having 
traversed  their  glands,  discharge  into  the  right  thoracic  or  brachio- 
cephalic trunk,  or  else  near  it  into  the  right  internal  jugular,  or  into 
the  right  subclavian  vein.  There  are,  in  these  respects,  diversities 
in  different  subjects. 

The  trunks  of  the  Absorbents  of  the  Heart  follow  the  course  of 
the  coronary  vessels,  and  distribute  themselves  by  branches  over  its 
whole  surface.  They  are,  without  previous  management,  easily 


* Loc.  cit.  p.  194. 


f Cruikshank,  loc.  cit. 


% Ibid. 


336 


ABSORBENT  SYSTEM. 


discovered ; but  if  the  heart  be  macerated  in  water  for  several  days, 
so  as  to  become  somewhat  putrid,  the  absorbents  are  filled  and  dis- 
tended by  the  gaseous  exhalation : on  the  puncture  of  one  of  these 
vessels  and  the  introduction  of  a pipe,  they  may  all  be  readily 
filled. 

There  are  three  principal  trunks  of  these  absorbents ; one  follows 
the  right  coronary  artery  to  the  root  of  the  aorta,  and  then  ascends 
over  the  front  surface  of  the  latter  to  the  top  of  its  arch,  where  it 
enters  a gland.  The  other  two  trunks  follow  the  two  principal 
branches  of  the  left  coronary  artery,  and,  coalescing  near  its  origin, 
they  ascend  to  the  bifurcation  of  the  pulmonary  artery,  and  from  that 
along  the  posterior  face  of  the  arch  of  the  aorta,  to  enter  a gland 
between  it  and  the  trachea.  These  several  vessels  subsequently 
traverse  the  lymphatic  glands  about  the  trachea,  common  to  the 
heart  and  to  the  lungs : and  ultimately  terminate  under  varied  cir- 
cumstances, either  directly  or  indirectly,  in  the  left  thoracic  duct, 
the  left  internal  jugular,  or  the  left  subclavian  vein.  Mr.  Cruikshank 
says,  that  the  right  coronary  trunk  empties  into  the  lymphatic  trunks 
of  tlie  right  side  of  the  neck,  which  shows  that  there  is  no  fixed 
arrangement. 

The  Absorbents  of  the  Pericardium  may  also  be  found  ; they  ter- 
minate like  the  others  of  the  heart,  in  the  bronchial  glands,  and  are 
particularly  associated  with  those  of  the  thymus  gland. 

The  Absorbents  of  the  (Esophagus  are  so  numerous  as  to  form  a:, 
plexus  from  one  end  to  the  other  of  it.  They  run  into  the  bronchial 
glands,  and,  therefore,  have  a common  termination  with  the  absor- 
bents of  the  heart  and  lungs.  Mr.  Cruikshank  says,  that  he  has 
reason  to  believe  that  he  has  seen  life  sustained  through  them  alone 
and  the  absorbents  of  the  mouth,  in  a case  where  stricture  prevailed 
for  some  months  just  above  the  cardia,  and  where  the  food,  after 
remaining  for  three  or  five  minutes  in  the  oesophagus,  was  vo- 
mited up.* 

The  Absorbents  of  the  Thymus  Gland  are  very  abundant  in  the 
infant,  but  diminish  with  the  rest  of  the  structure  in  the  adult : they 
terminate  in  the  bronchial  glands  also. 


* A,  case  somewhat  similar  occurred  in  the  practice  of  Dr.  Physick. 


ABSORBENTS  OF  THE  PARIETES  OF  THE  TRUNK. 


337 


SECT.  VII. — ABSORBENTS  OF  THE  PARIETES  OF  THE 
TRUNK. 

In  addition  to  the  absorbents  mentioned  as  belonging  to  the  in- 
ternal and  external  parietes  of  the  pelvis,  there  are  some  others 
belonging  to  this  cavity,  as  the  ilio  lumbar,  the  sacral,  and  the  cir- 
cumflex. 

The  Ilio  Lumbar  Lymphatics  come  from  the  parts  to  which  the 
artery  of  the  same  name  is  distributed,  and,  assembling  into  two  or 
more  large  trunks  which  pass  beneath  the  psoas  magnus  muscle, 
one  of  them  joins  the  lumbar  glands,  and  another  the  hypogastric. 

The  Sacral  Lymphatics  arise  from  the  cellular  tissue  in  front  of 
the  sacrum  and  from  the  spinal  canal  in  the  latter.  Emerging 
through  its  foramina  in  front,  they  terminate  in  the  lower  part  of  the 
lumbar  and  in  the  hypogastric  plexus. 

The  Circumflex  Iliac  Lymphatics  attending  the  artery  of  the  same 
name,  arise  from  the  lateral  inferior  parietes  of  the  abdomen,  in  the 
thickness  of  its  broad  muscles ; the  several  branches  assemble  into  a 
few  trunks,  which  descend  along  the  posterior  margin  of  Poupart’s 
ligament  to  terminate  in  the  external  iliac  plexus. 

The  Epigastric  Absorbents  are  derived  from  the  inferior  anterior 
parietes  of  the  abdomen,  along  the  region  of  distribution  of  the  epi- 
gastric artery.  Their  trunks  coalesce  into  larger  ones,  and  descend 
along  this  artery  to  end  in  the  external  iliac  plexus,  near  the  crural 
arch. 

The  Lumbar  Absorbents  arise  from  the  muscles  of  the  loins, 
from  the  posterior  part  of  those  of  the  abdomen,  and  from  the  spinal 
cavity.  Their  trunks  correspond  with  the  lumbar  arteries,  and 
passing  beneath  the  psoas  magnus  muscle  towards  the  spine,  they 
terminate  in  the  lumbar  glands. 

The  Intercostal  Absorbents  take  their  origin  from  the  parietes  of 
the  thorax,  and  following  the  course  of  the  respective  intercostal 
arteries,  pass  through  some  small  glands  occasionally  found  be- 


338 


ABSORBENT  SYSTEM. 


tween  the  external  intercostal  muscles  near  the  heads  of  the  ribs. 
They  are  there  joined  by  trunks  from  the  spinal  cavity  and  from  the 
muscles  of  the  back,  and  afterwards  passing  through  some  small 
glands  on  the  front  of  the  vertebral  column,  they  anastomose  more 
or  less  with  one  another,  and  finally  terminate  in  the  left  thoracic 
duct.  The  absorbents  of  the  pleura  costalis  and  of  the  posterior 
part  of  the  pericardium  terminate  in  the  intercostals. 

The  Internal  Mammary  Absorbents  have  their  roots  in  the  ante- 
rior region  of  the  parietes  of  the  abdomen,  above  the  umbilicus, 
where  they  anastomose  with  the  epigastric.  They  ascend,  along 
with  the  internal  mammary  arteries,  behind  the  sternal  cartilages, 
pass  through  some  small  glands,  and  receive  contributions  from  the 
anterior  extremities  of  the  intercostal  spaces.  Those  of  the  left  side, 
assembling  into  one  or  two  trunks,  cross  in  front  of  the  left  sub. 
clavian  vein,  traverse  the  inferior  cervical  glands,  descend  after- 
wards from  this  point,  and  terminate  in  the  left  thoracic  duct,  or  in 
one  of  the  contiguous  trunks  of  the  venous  system.  Those  on 
the  right  execute  the  same  movements,  but  terminate  in  the  right 
thoracic  duct,  or  in  one  of  the  contiguous  venous  trunks  on  that 
side. 

The  Absorbents  of  the  Diaphragm  are  exceedingly  numerous, 
and  very  much  connected  with  those  of  the  liver.  The  anterior 
ones  join  the  internal  mammary  absorbents,  while  the  posterior  fol- 
low the  phrenic  arteries,  or  go  to  contiguous  trunks  belonging  to  the 
intercostals.  The  front  ones  on  the  right  side,  then  terminate  in  the 
right  thoracic  duct,  while  the  remainder  go  in  the  various  routes  of 
the  absorbents,  with  which  they  are  connected,  into  the  left  thoracic 
duct.  They  are  principally  seen  on  its  upper  surface.  Mr.  Cruik- 
shank*  says,  that  he  once  saw  them  to  the  amount  of  three  hundred 
or  more,  filled  with  chyle  from  the  mesentery  that  had  passed 
through  the  substance  of  the  liver.  Asellius  was,  therefore,  probably 
justified  by  an  accident  of  this  kind,  in  asserting  that  the  lacteals 
went  to  the  liver. 

The  Absorbents  of  the  Female  Mammae,  like  their  arteries  and 
veins,  are  superficial  and  deep  ; the  former  attend  the  external  tho- 


* Loc.  cit.  p.  90. 


THORACIC  ABSORBENTS. 


339 


racic  blood  vessels,  and  the  latter  the  internal  mammary.  The 
superficial  arise  from  the  circumference  of  the  nipple,  from  the  skin 
and  cellular  membrane,  and  according  to  the  injections  of  Mr.  Cruik- 
shank,  communicate  freely  with  the  vesicles  of  the  tubuli  lactiferi. 
They  run  towards  the  axilla,  having  occasionally  to  pass  through 
some  glands  which  are  situated  half  way ; they  then  enter  the  first 
series  of  glands  of  the  axilla  in  their  direction,  and  afterwards  others 
successively,  until  they  terminate  in  the  lymphatic  trunks  of  the  up- 
per extremity,  high  up  in  the  arm-pit.  Some  few  of  these  superficial 
vessels  ascend  over  the  pectoralis  major  to  the  glands  in  the  neck, 
just  above  the  clavicle. 

The  deep  absorbents  of  the  mammse  arise  from  their  thoracic  face, 
and  penetrating  the  intercostal  spaces,  join  the  absorbents  that  at- 
tend the  internal  mammary  artery. 

Of  the  Absorbent  Glands  in  the  Thorax. 

There  are,  as  mentioned,  a few  small  glands  in  the  intercostal 
spaces  near  the  heads  of  the  ribs  between  the  internal  and  external 
intercostal  muscles,  intended  to  receive  the  lymphatics  of  these 
spaces.  There  are  also  several  small  ones  situated  on  the  front  of 
the  dorsal  vertebrae,  along  the  aorta  and  the  oesophagus,  in  the  pos- 
terior mediastinum.  There  are  also  from  six  to  ten  along  the  in- 
ternal mammary  artery  ; and  some  others  in  the  anterior  mediastinum, 
along  the  sternal  face  of  the  pericardium.  They  are  said  to  be  very 
rarely  affected  by  disease. 

The  most  considerable  and  striking  glands  in  the  thorax  are  those 
called  Bronchial  or  Pulmonary,  which  receive  the  absorbents  of  the 
lungs.  They  cluster  about  the  bifurcation  of  the  trachea,  and  follow 
the  bronchia  for  some  distance  into  the  substance  of  the  lungs.  They 
are  from  ten  to  twenty  in  number,  and  vary  in  size  from  an  inch  to 
a few  lines  in  diameter.  Till  puberty  they  have  a reddish  colour, 
but  afterwards  they  become  gray,  and  finally  black,  following  in 
these  respects  the  change  of  colour  in  tire  lungs.  According  to  Mr. 
Pearson,  their  complexion  depends  upon  the  deposit  of  pure 
carbon. 

In  pulmonary  consumption  these  glands  are  always  enlarged,  and 
look  scrofulous. 


340 


ABSORBENT  SYSTEM. 


SECT.  VIII. — OF  THE  THORACIC  DUCTS.* 

The  Left  Thoracic  Duct  ( Ductus  Thoracicus  Sinister ) is  the  main 
stream  of  the  absorbent  system  to  which  almost  all  the  others  are 
but  tributary,  and  by  divers  routes  ultimately  find  their  way  into  it. 
It  begins  about  the  second  or  third  lumbar  vertebra,  in  front  of  its 
body.  Shortly  after  its  commencement,  while  still  in  the  abdomen, 
it  suffers  a dilatation  more  or  less  considerable,  and  varying  in  its 
shape  in  different  subjects.  This  is  called  the  Reservoir  of  Pecquet, 
or  the  Receptaculum  Chyli ; the  dilatation,  however,  is  frequently 
absent,  and  does  not  seem  to  be  an  essential  part  of  the  structure: 
in  our  preparations  at  the  University  some  have  it,  and  others  have 
it  not. 

The  thoracic  duct  enters  the  thorax  between  the  crura  of  the  dia- 
phragm, to  the  right  of,  and  behind  the  aorta ; it  then  ascends  on 
the  front  of  the  dorsal  vertebra,  between  the  aorta  and  the  vena 
azygos,  in  front  of  the  right  intercostal  arteries,  and  behind  the 
oesophagus.  At  the  fourth  dorsal  vertebra  it  begins  to  incline  in  its 
ascent  to  the  left  side,  and  then  ascends  into  the  neck  near  the  head 
of  the  first  rib ; it  rises  commonly  as  high  up  as  the  upper  margin  of 
the  seventh  cervical  vertebra ; it  then  turns  downwards  and  forwards, 
over  the  left  subclavian  artery  within  the  scaleni  muscles,  and,  finally 
discharges  into  the  angle  of  junction  of  the  left  subclavian  and  in- 
ternal j ugular  vein. 

The  preceding  is  the  most  simple,  and  perhaps  the  most  common 
form,  under  which  the  thoracic  duct  is  presented,  but  varieties  are 
continually  occurring  in  its  place  and  mode  of  origin,  in  its  trunk, 
and  its  manner  and  place  of  termination.  It  commonly  begins  by 
the  union  of  three  absorbent  trunks ; one  for  each  side  of  the  pelvis, 
along  with  the  corresponding  lower  extremity;  and  a middle  one  for 
the  chyliferous  vessels,  which  unites  with  the  common  trunk  of  the 
other  two,  a few  lines  above  its  point  of  formation ; on  other  occa- 
sions, the  chyliferous  trunks  join  it  in  a confused  manner  by  nine  or 
ten  distinct  channels.  Sometimes  an  intricate  plexus  of  several 
large  trunks;  derived  from  the  lumbar  and  mesenteric  glands,  by 
the  gradual  reduction  of  the  number  of  meshes  from  the  successive 
joining  of  trunks;  begins  to  assume,  at  the  crura  of  the  diaphragm, 


* Anat.  Atlas,  Fig.  502. 


THORACIC  DUCTS. 


341 


the  form  of  a solitary  trunk,  which  is  the  thoracic  duct.  The  trunk 
of  the  duct  is  also  disposed  to  keep  up  the  anastomosing  plan,  even 
in  the  thorax  ; we  hence  see  it  sometimes  dividing  itself  into  two  or 
three  channels  of  equal  size,  which  unite  again  after  a shorter  or 
longer  distance,  and  perhaps  in  a little  space  repeat  the  same  ar- 
rangement : sometimes  a small  arm  is  sent  off,  which  runs  along  for 
an  inch  or  two,  and  joins  into  the  parent  stream;  sometimes  spiral 
turns  are  adopted  by  the  thoracic  duct ; sometimes  nodosities,  or 
small  pouches  are  formed  on  its  sides ; sometimes  it  is  dilated  at  in- 
tervals in  its  whole  circumference.  Sometimes  it  splits  into  several 
channels  at  its  termination ; one  channel  terminating  in  one  vein  and 
another  in  a contiguous  one,  of  the  several  trunks  forming  the  vena 
innominata ; on  other  occasions,  instead  of  entering  into  a venous 
trunk  of  the  left  side,  it  goes  into  the  corresponding  one  of  the 
right. 

Commonly,  it  is  about  the  size  of  a large  crow-quill,  but  some- 
times as  large  as  a goose-quill,  or  even  still  more  voluminous,  seem- 
ing to  be  in  a varicose  state,  of  which  Mr.  Cruikshank  mentions  an 
example  where  it  was  half  an  inch  in  diameter,  and  took  two  pounds 
of  mercury  to  fill  it.  There  is  generally  a pair  of  valves  at  the  ter- 
mination of  the  thoracic  duct,  or  if  it  be  divided  into  several  streams 
there  is  a pair  at  the  embouchure  of  each,  to  keep  the  venous  blood 
out  of  it.  There  are  also  valves  in  its  length,  but  they  are  not 
numerous,  and  vary  in  different  subjects. 

The  thoracic  duct,  as  stated,  is  the  grand  outlet  for  the  lymphatics 
of  the  left  side  of  the  head  and  neck,  of  the  left  superior  extremity, 
of  the  left  side  of  the  thorax,  of  all  the  intercostal  spaces,  of  the 
viscera  of  the  abdomen,  and  of  the  inferior  extremities.  Though 
those  of  the  viscera  of  the  abdomen  and  of  the  lower  extremities 
have  this  route,  yet,  from  the  observations  of  Mr.  Lippi,  of  Florence, 
as  mentioned,  they  have  also  some  more  direct  means  of  getting  into 
the  general  circulation.  For  example,  he  has  found  several  large 
lymphatic  trunks  emptying  into  the  ascending  cava,  one  of  them 
opposite  the  third  lumbar  vertebra;  another  into  the  primitive  iliac 
vein : he  has  also  found  some  of  the  lymphatics  of  the  liver  dis- 
charging into  the  vena  portarum. 

The  Right  Thoracic  Duct,  ( Ductus  Thoracicus  Dexter,)  as  it  is 
called,  but  more  properly  the  Right  Brachio-cephalic,  after  the  name 
given  by  M.  Chaussier  to  the  vein,  is  not  more  than  an  inch  long, 
and  descends  to  empty  itself,  as  mentioned,  into  the  junction  of  the 

Vol.  II.— 30 


342 


ABSORBENT  SYSTEM. 


right  interna]  jugular  with  the  right  subclavian  vein.  It  is  derived 
from  the  lymphatic  trunks  of  the  right  side  of  the  head  and  neck,  of 
the  right  upper  extremity,  the  superficial  lymphatics  of  the  right  side 
of  the  thorax,  the  lymphatics  of  the  right  lung,  of  the  right  side  of 
the  diaphragm,  and  some  of  those  of  the  right  side  of  the  liver,  the 
courses  of  all  of  which  have  been  detailed. 

Though  the  single  trunk  is  formed  from  these  several  tributary 
streams,  yet  the  latter  have  sometimes  several  embouchures  into  the 
venous  system  at  or  near  the  point  mentioned,  and,  as  on  the  other 
side  of  the  body,  there  is  a proper  security,  by  valves  from  the  in- 
troduction of  blood  into  them. 

There  is  always  an  ample  system  of  anastomosis,  not  only  between 
the  branches  which  concur  to  form  the  right  and  left  thoracic  ducts, 
but  even  between  the  ducts  themselves,*  so  that  if  one  be  occluded 
or  impeded,  its  circulation  can  be  turned  into  the  other,  as  in  the 
case  of  veins. 


* Meckel,  Man.  D’Anat.,  tom.  ii.,  p.  581. 


BOOE  IX* 


PART  f. 


HISTOLOGY  OF  THE  NERVOUS  SYSTEM, 


Nervous  System. 

The  Essential  ingredient  of  this  System  is  a peculiar  animal  matter 
called  Neurine , the  texture  of  which  is  so  soft,  that  in  the  natural 
state  it  has  the  least  possible  consistence.  It  is,  therefore,  protected 
in  a variety  of  ways ; by  being  enclosed  in  bone,  where  it  is  collected 
in  large  masses  ; and  by  being  surrounded  by  ligamentous  or  cellular 
matter,  where  flexure  is  required. 

The  nervous  system  in  man,  and  other  vertebrated  animals,  con- 
sists in  two  portions  of  dissimilar  forms ; one  is  spheroidal,  elongated 
at  its  base  into  a cylindrical  process,  and  is  contained  in  the  cranium 
and  in  the  spinal  canal ; the  other  is  an  assemblage  of  arborescent 
rays,  which  proceed  from  different  points  of  the  first  portion,  to 
every  part  of  the  body.  The  first  portion  is  the  Central  or  Internal 
part  of  the  nervous  system,  composed  of  the  Brain  and  Spinal 
Marrow  ; while  the  radiating  portion  is  called  the  External  or  Peri- 
pheral, and  consists  in  the  Nerves  of  the  brain  and  spinal  marrow. 

The  nervous  system  is  remarkable  for  its  symmetry.  As  it  is  uni- 
versally double,  it  very  seldom  happens  that  any  striking  difference 
of  it  on  the  two  sides  of  the  body  is  manifested,  particularly  as  re- 
gards its  Central  portion ; it  is  said,  however,  that  aberrations,  in 
this  respect,  are  more  common  in  man  than  in  other  mammiferous 
animals. 


344 


NERVOUS  SYSTEM. 


The  central  portion  of  the  nervous  System  is  composed  of  two 
kinds  of  the  substance  called  Neurine,  distinguished  by  their  colour 
and  relative  situation : one  is  improperly  enough  called  Medullary, 

( Substantia  Medullaris ,)  but  as  the  name  is  now  sanctioned  by  uni- 
versal usage,  it  is  impossible  to  dispense  with  it.  The  other  is  called 
Cineritious,  ( Substantia  Cinerea ) with,  perhaps,  sufficient  propriety, 
from  its  colour.  They  are  both  of  a soft  pulpy  consistence,  and 
constitute  the  chief  mass  of  the  brain  and  spinal  marrow:  some  an- 
atomists have  desired  to  add,  from  a slight  distinction  of  colour, 
two  other  substances,  a yellow  and  a black,  but  that  seems  unne- 
cessary, and  has  not  been  generally  acknowledged.  These  sub- 
stances differ  from  one  another  in  regard  to  their  quantity,  the  me- 
dullary being  more  abundant  than  the  cineritious  ; it  is  also  harder, 
and  receives  fewer  vessels. 

The  cineritious,  or  gray  substance  of  the  brain  and  spinal  chord 
is  formed  of  globules,  according  to  Valentin,  of  a spheroidal  shape. 
These  globules  have  a nucleus,,  and  in  the  circumference  of  this  a 
nucleolus.  The  quantity  of  these  globules  determines  the  shade  of 
the  gray  substance,  but  there  are  parts  of  the  latter  of  a darker  colour 
which  is  owing  to  a pigment  of  the  globule. 

It  is  thought  by  Muller,  that  the  cineritious  globules  of  the  nervous 
system  are  connected  together  by  peculiar  filaments ; the  same  ar- 
rangement existing,  in  the  ganglia  of  nerves. 

The  Medullary  Matter,  when  quite  fresh  and  scraped  in  particular 
directions  has  a filamentous  condition,  which  may  be  rendered  still 
more  distinct  by  hardening  it  in  alcohol,  in  boiling  oil,  in  a solution 
of  the  neutral  salts,  or  im  diluted  mineral  acids.  If  an  attempt  be 
then  made  to  tear  it,  it  will  be  immediately  perceived  that  the  fibres 
separate  in  a fixed  direction,  and  in  no  other.  These  fibres,  are,  in 
some  instances,  parallel ; in  others,  concentric  ; and  in  others,  di- 
verging or  converging.* 

The  elementary  form  of  white  nervous  matter  consists  in  those  fila- 
ments or  threads,  and  which  in  the  nerves  are  held  together  by  cellular 
substance.  Each  filament  in  both  the  brain  and  the  nerves  consists 
in  a membranous  tube,  containing  a soft  matter.  In  the  brain  the 

* See  Lessons  on  Practical  Anatomy,  by  W.  E.  Horner,  for  description  of 
Brain  according  to  Gall  and  Spurzheim. 


HISTOLOGY  OF  THE  NERVOUS  SYSTEM. 


345 


latter  is  a mere  pulp,  but  in  the  nerves  it  may  be  separated  from  its 
tube  in  a linear  form  for  some  distance. 

The  fibres  or  filaments  of  the  brain  when  pressed  upon,  become 
swollen  at  intervals  so  as  to  be  knotted  or  like  a string  of  beads, 
and  if  the  pressure  be  much  they  are  separated  into  globules  of  dif- 
ferent sizes.  The  elementary  nervous  fibres  are  smaller  in  the  brain 
and  spinal  marrow  than  elsewhere ; in  the  nerves  themselves  they 
vary  from  <r  to  is?  of  an  English  line. 

The  knotted  appearance  upon  compression  of  the  cerebral  sub- 
stance and  spinal  marrow  observed  by  Ehrenberg  first,  is  also  ascer- 
tained by  him  to  belong  to  the  nerves  of  special  sensation,  as  the 
Olfactory,  Optic,  and  Auditory.  The  sympathetic  has  also,  to  a 
limited  degree,  this  feature.  It  was  at  first  supposed  to  be  from  some 
peculiar  attribute,  but  now  is  accounted  for  by  the  greater  delicacy 
at  points,  of  the  investing  membrane  of  the  filaments. 

The  two  substances  are  variously  placed  in  different  parts  of  the 
nervous  system : the  surface  of  the  cerebrum  and  of  the  cerebellum 
is  formed  by  the  cineritious  matter,  and  the  interior  principally  by 
medullary ; while  the  surface  of  the  pons,  of  the  crura,  and  of  the 
spinal  marrow,  is  medullary,  and  their  interior  cineritous.  Again,  in 
other  points,  they  are  intermixed.  The  medullary  matter  is  al- 
ways so  arranged  that  it  is  never  interrupted,  but  forms  a con- 
tinuous whole ; while  the  cineritious  is  in  detached  masses,  and  is 
found  where  the  central  extremities  of  the  nerves  are  implanted, 
or  where  there  is  an  increase  of  medullary  fibres.  Some  ana- 
tomists have  even  supposed  that  it  existed  at  tire  peripheral  ex- 
tremity of  the  nerves,  and  particularly  in  the  rete  mucosum  of  the 
skin. 

The  fibrillar  of  the  medullary  tissue  are  united  by  a very  fine  and 
thin  cellular  substance,  which  may  be  seen  by  tearing  them  apart. 
This  cellular  substance  is  more  condensed  near  the  surface  of  the 
brain,  where  it  is  formed  into  a highly  vascular  membrane,  the  pia 
mater,  and  is  continued  along  the  nerves  as  a neurileme,  or  covering 
to  them. 

All  nervous  fibres  are  exactly  cylindrical  though  this  shape  is 
easily  disturbed  by  the  manner  of  examining  them.  When  tested 
carefully,  no  doubt  is  left  on  this  head,  and  especially  if  the  fibre 
be  taken,  as  suggested  by  Muller,  from  the  Valve  of  the  Brain.  The 
varicose  or  knotted  condition  may  be  evolved  possibly  by  a species 

30* 


NERVOUS  SYSTEM. 


3 £6 

of  contractility  being  brought  into  play  by  the  method  of  examina- 
tion, of  which  we  have  an  example  on  a large  scale  in  the  Medulla 
Spinalis,  which  when  taken  from  the  spinal  canal  becomes  corru- 
gated by  a spontaneous  contraction. 

Vauquelin’s  chemical  analysis  of  the  brain  afforded  the  following 
results : 

7.00 

5.23 

1.50 
1.12 
5.15 
80. 


100.00 

The  Central  Nervous  system  is  abundantly  supplied  with  blood 
vessels,  but  lymphatic  trunks  have  not  yet  been  injected  in  it. 

The  Peripheral  Portion  of  the  Nervous  System  or  the  Nerves, 
are  formed  by  parallel  anastomosing  fasciculi  of  fibres,  perceptible 
to  simple  inspection,  which  may  be  reduced  into  fibrillae,  and  then 
again  into  filaments  as  small  as  the  thread  of  a silk  worm.  The 
finest  filament  is  enclosed  in  its  appropriate  sheath,  so  that  the  latter 
is  a tube  filled  with  nervous  matter.  The  nervous  matter  is  soluble 
in  an  alkali,  and  in  that  way  may  be  removed ; the  canals  may  then 
be  filled  with  quicksilver  or  air,  and  their  existence  demonstrated. 
On  the  other  hand,  nitric  or  muriatic  acid  dissolves  the  sheath, 
but  hardens  the  nervous  matter,  and  renders  it  more  distinct,  so  that 
the  finest  filaments  are  made  obvious.*  In  either  case  it  is  evi- 
dent that  the  shape  of  the  nerve  is  preserved.  These  filaments  are 
supposed  to  be  precisely  the  same  with  the  fibres  of  the  brain, 
excepting  that  their  sheaths  keep  them  more  distinct  from  one 
another. 

The  Primitive  fibres  of  the  nerves  have  close  correspondence  in 
ill  animals,  being  solely  threads  and  never  globular. 


$ Stearin 
) Elain 


Albumen 

Adipose  matter 

Phosphorus  - 
Osmazome  - 
Acids,  Salts,  and  Sulphur 
Water 


4.53 

.70 


* Eeil,  de  Struct,  N.erv. 


HISTOLOGY  OF  THE  NERVOUS  SYSTEM.  347 

The  original  observation  on  the  tubular  structure  of  the  nerves 
and  brain,  is  due  to  Fontana,  since  then  it  has  been  confirmed  by 
numerous  others,  as  Remak,  Henle,  Valentin,  &c.,  so  that  it  may 
now  be  considered  as  one  of  the  well-ascertained  points  of  anatomy. 

The  cerebro-spinal  nerves  contain  a small  intermixture  of  gray 
fibres,  derived,  probably,  from  ganglionic  globules.  The  sympa- 
thetic has  in  return,  though  principally  formed  of  grayish  fibres, 
some  few  white  fibres.  In  the  common  nerves  this  modification 
by  the  presence  of  gray  fibres  is  seen  principally  at  the  points  of 
junction  with  the  sympathetic. 

The  sheath  of  the  nerves,  or  the  Neurileme  ( Neurilemma ) forms 
a general  envelope  to  the  nervous  fasciculi,  as  well  as  a particular 
one  to  each  fibre,  and  is  continuous  at  its  central  extremity,  with 
the  pia  mater.  Its  divisions  branch  off  and  unite  again  at  intervals, 
fofining  a species  of  reciprocal  anastomosis,  sufficiently  represented 
by  the  plan  of  the  large  nervous  plexuses,  as  they  occur  in  various 
parts  of  the  body.  It  is  the  general  envelope  which  is  obviously 
continuous  with  the  pia  mater,  but  the  particular  sheaths  of  the  finer 
fibres  are  lost  insensibly,  so  that  these  fibres  appear  naked  in  the 
centre  of  the  nerve,  at  its  central  extremity,  unless  examined  with 
a good  glass.  The  same  destitution  of  neurilematic  covering  is  ob- 
servable at  the  peripheral  extremities  of  the  nerves,  wherever  the 
latter  can  be  traced.  The  interior  of  these  canals  is  traversed  by 
processes  which  cross  the  nervous  matter  and  sustain  it.  From  the 
increase  in  size,  the  additional  solidity,  and  the  close  adhesion  of 
the  nerves  to  the  dura  mater,  where  they  pass  out  of  their  several 
foramina  in  the  spine  and  cranium,  there  is  no  doubt  that  the  dura 
mater  contributes  to  the  neurileme,  though  its  structure  is  altered  and 
made  much  less  dense.  The  best  evidence'  of  this  is  the  sheath  of 
the  optic  nerve,  and  of  the  spinal  nerves.  This  opinion,  advanced 
by  the  ancients-,  has  been  strongly  contested  by  Haller,*  and  by 
Zinn.f  The  tunica  arachnoidea  is  too  fine  to  admit  of  any  positive 
opinion  about  tire  extent  to  which  it  follows  the  nerves. 

The  neurileme  has  but  little  contractility,  is  solid  and  difficult  to 
tear,  and  is  supposed  to  be  the  secretory  organ  of  the  medullary 
substance. 


* Prim.  LLm- 


fr  Memoires  de  Berlin,  1753*. 


34S 


NERVOUS  SYSTEM. 


The  nervous  fasciculi  are,  moreover,  held  together  by  cellular 
substance,  which  has  in  the  progress  of  life,  a tendency  to  the  de- 
positing of  fat.  This  cellular  substance,  in  neuralgic  affections,  is  sub- 
ject to  infiltrations  and  redness,  whereby  it  becomes  hard.  This 
circumstance  has  induced  pathologists  to  consider  the  pain  as  de- 
pending upon  its  inflammation.* * * § 

The  optic  nerve,  owing  to  the  size  of  its  canals,  furnishes  the  best 
example  of  structure,  and  the  nerves  of  the  muscles  are  next.  There 
are,  however,  some  peculiarities  in  different  nerves ; as  the  obser- 
vations of  Sir  Everard  Home  have  ascertained  that  the  medullary 
filaments  of  the  optic  nerve  augment  in  numbers  and  diminish  in 
volume,  from  its  origin  towards  its  termination.  The  early  light 
thrown  upon  these  minute  and  interesting  points  of  nervous  organi- 
zation, has  been  derived  from  the  researches  of  Reil  and  Fontana. f 

In  addition  to  the  preceding  structure,  the  nerves  present  a satin- 
like undulated  surface,  with  small  bands  that  pass  somewhat  spirally 
and  in  a zigzag  direction.  The  latter  appearance  is  illusory,  and 
depends  upon  the  contraction  or  shortening  of  the  nerve  when  not 
stretched  ; its  seat  is  in  the  neurileme,  and  it  accordingly  disappears, 
upon  extension. 

Some  years  ago  M.  M.  Prevost  and  Dumas  asserted  that  they 
had  found  the  ultimate  filaments  of  nervesf  as  distributed  to  muscles, 
terminating  in  loops,  either  by  anastomosis  with  other  filaments  or 
in  a loop  of  the  individual  filament.  The  observations  of  Valentin 
and  Emmert  corroborate  those  of  the  preceding  gentlemen.  Va- 
lentin has  found  the  same  arrangement  in  the  iris  and  in  the  ciliary 
ligament ; in  the  cochlea  of  birds ; in  the  sacs  of  the  teeth  ; and  in 
the  skin  of  the  frog.  This  arrangement  does  not,  however,  exist  as  a 
universal  one  in  the  nerves  of  sensation,  as  in  the  retina  of  the  verte- 
brated  animals  and  of  insects  :§  in  many  of  the  nervous  filaments  of 
the  labyrinth,  which  like  those  of  the  retina  have  a free  extremity ; 
and  also  in  the  pituitary  membrane,  according  to  Treviranus.  In 
the  mesentery  of  the  frog  the  nerves  terminate  in  a net-work  accord- 
ing to  Schwann. 

* Beclard,  Anat.  Gen.  p.  665. 

j-  Reil,  de  Structure  Nervorum.  Hal®  Saxonum,  1796.  Henle,  Remak, 
Valentin  and  several  others,  all  of  more  modern  date,  have  confirmed  more  of 
less  the  views  of  Reil  and  added  to  them. 

\ See  Histology  of  Muscles. 

§ Muller’s  Report  on  Nervous  System. 


HISTOLOGY  OF  THE  NERVOUS  SYSTEM. 


349 


The  nerves  abound  in  blood  vessels ; when  a vascular  trunk 
reaches  them,  one  of  its  branches  ascends  and  another  descends, 
and,  if  successfully  injected,  the  neurileme  is  covered  by  its  capil- 
lary ramifications.  As  in  the  brain,  the  lymphatics  have  not  yet 
been  injected. 

There  are  three  modes  by  which  the  nervous  fasciculi  unite  with 
one  another ; anastomosis,  plexus,  and  ganglion.  Anastomosis  is 
the  junction  of  the  filaments,  either  of  the  same  nerve  or  of  different 
nerves,  and  the  examples  of  it  are  very  abundant.  Plexus  is  an  anas- 
tomosis on  a larger  scale,  and  occurs  between  the  larger  fasciculi  of 
the  same  nerve,  or  of  different  nerves,  whereby  a very  complete  inter- 
texture of  their  fibres  occurs. 

Kronenburg  asserts  that  the  primitive  fibres  of  the  cerebral  nerves 
continue  separate  up  to  their  ultimate  distribution,  and  that,  in  their 
apparent  union,  they  only  change  from  one  fasciculus  to  another, 
and  that  this  arrangement  prevails  not  only  in  the  plexus,  but  in 
every  part  of  the  nervous  trunk  and  its  branches.  This  conclusion 
he  founds  upon  his  observations  of  the  brachial  plexus  in  mamma- 
lia, and  of  the  lumbar  plexus  in  the  frog.*  This  opinion,  first  ad- 
vanced by  Fontana,  has  now  been  so  repeatedly  proved  by  observa- 
tion up  to  the  present  time,  that  it  is  laid  down  as  an  axiom  in  ana- 
tomy that  from  whatever  point  a nervous  fibre  may  arise,  it  runs  to 
its  termination  as  a thread  without  coalition  with  any  other  fibre. 
It  hence  happens  that  the  innumerable  points  of  origin  for  the  nerves, 
have  equally  numerous  points  or  places  of  termination,  on  the  peri- 
pheral parts  of  the  body.  The  accuracy  of  our  sensations  and  of 
nervous  intercommunication  is  supposed  to  depend  essentially  upon 
this  distinction  being  observed  ;•  otherwise  the  impressions  would  be 
of  tire  most  confused  kind,  and,  as  Muller  observes,  no  local  im- 
pression on  a single  definite  point  would  be  perceived  by  the 
brain,  f 

The  above  rule,  though  now  established  for  the  white  fibres  of 
the  brain  and  spinal  marrow,  is  not  so  fixed  for  the  gray  fibres, 
as  there  is  some  doubt  whether  they  may  not  be  connected  in  the 
ganglia. 

Ganglions  are  knots  which  occur  in  the  course  of  nerves,  whereby 

* Muller’s  Report  on  Nervous  System,  p.  232,  for  the  year  183G. 

f Page  G51. 


350 


NERVOUS  SYSTEM. 


they  have,  for  the  time,  a great  augmentation  of  volume.  The  gan- 
glions have  a great  variety  of  form  and  size ; they  are  parabolic, 
circular,  crescentic  and  so  on,  and,  in  their  general  appearance, 
hardness,  and  colour,  resemble  somewhat  lymphatic  glands.  When 
submitted  to  maceration,  they  are  resolved  into  two  kinds  of  sub- 
stance : one  is  filamentous  and  continuous  with  the  nerves,  adhering 
to  the  ganglion  ; and  the  other  is  gelatinous  in  its  consistence  and 
of  a reddish  ash  colour.  The  filaments,  in  penetrating  the  ganglions 
are  deprived  of  their  strong  neurileme,  which  is  continued  into  a 
sort  of  capsule  that  surrounds  the  ganglions.  They  pass  uninter- 
ruptedly, through  the  ganglion,  and, 
therefore,  continue  the  several  nervous 
chords  into  one  another ; but,  in  a 
complicated  way.  The  elementary 
arrangement  of  the  nervous  ganglia 
consists  in  grayish  matter  of  the  same 
description  with  that  in  the  brain ; and 
of  nervous  filaments  in  continuation 
with  the  nerves  connected  with  the 
ganglion.  The  nerves  are  resolved 
into  a very  fine  intertexture  or  plexus 
which  forms  its  meshes  around  the 
globules  of  gray  matter,  and  are  then 
recomposed  to  pass  out  on  the  other 
side  of  the  ganglion.  The  ganglions,  like  other  parts  of  the  nervous 
system,  are  very  vascular. 

The  Ganglions  are  said  to  be  simple  and  compound ; the  first  is 
where  a single  nerve  produces  the  ganglion,  and  the  second  where 
the  filaments  of  two  or  more  nerves  concur  to  form  it.  The  simple 
ganglions  are  invariable  in  their  form  and  situations,  and  belong  to 
the  spinal  marrow,  being  formed  upon  the  posterior  fasciculi  alone  : 
this  fact  was  first  pointed  out  by  Haase,*  and  has  been  subsequently 
confirmed  by  the  observations  of  Scarpa  and  of  Prochaska,  and  by 
the  admission  of  anatomists  generally.  The  exterior  envelope  is 
continuous  with  the  dura  mater,  and  the  internal  with  the  pia 
mater,  from  whence  they  have  more  firmness  than  other  ganglions. 


Fig.  39 


Globules  of  the  gray  matter 
of  ganglia  after  Valentin.  In 
one,  a second  nucleus  is  visible. 
The  nucleus  of  several  contains 
one  or  two  nucleoli. 


* De  Gangliis  Nervorum.  Lipsia,  1772. 


HISTOLOGY  OF  THE  NERVOUS  SYSTEM. 


351 


The  compound  ganglions  are  found  at  divers  stations  about  the 
body. 

The  attention  of  the  profession  has  been  much  directed  latterly 
to  the  microscopical  observations  of  Professor  Ehrenberg,  of  Ber- 
lin, on  the  structure  of  the  Nervous  System.*  The  following  is  a 
summary  of  his  doctrines  on  this  subject.  The  instrument  used 
being  a microscope  of  Chevalier,  of  Paris,  augmented  in  power  by 
Pistor  and  Schiek,  of  Berlin. 

The  organic  structure  of  the  Encephalon,  the  Spinal  Cord,  and 
the  Nerves,  presents : 

1.  A set  of  straight  tubes,  like  a string  of  mock  pearl  beads,  and 
whose  spheroidal  enlargements  are  kept  apart  by  an  intermediate 
canal.  These  nodulated  tubes  he  calls  varicose,  from  their  mecha- 
nical conformation  or  resemblance  to  varicose  veins ; he  also  calls 
them  jointed  or  articulated  from  their  shape.  These  are  parallel  to 
one  another,  cross  occasionally,  are  never  seen  to  anastomose,  and 
are  like  filaments : they  contain  a peculiar  matter,  designated  the 
Nervous  fluid,  (Liquor  Nervosus  of  Haller,)  and  are  confined  chiefly 
to  the  wdiite  or  medullary  portion  of  the  Encephalon  and  Spinal 
Marrow.  They  are  of  a milky  colour. 

2.  A set  of  filamentous  bodies,  which  are  hollow  or  tubular,  of  a 
simple  cylindrical  shape,  that  is,  not  having  the  irregular  surface  or 
nodes  of  the  preceding.  They  are  uniform,  and  generally  larger 
than  the  nodulated,  though  the  latter  are  in  places  continued  into 
the  former.  They  contain  a white  viscid  fluid,  to  which  he  gives 
the  name  of  Medullary,  and  which  is  less  transparent  than  the  Ner- 
vous. These  tubes  are  the  one  hundred  and  twenty-ninth  of  a line 
thick  in  the  middle  ; they  are  elementary,  are  not  surrounded  indi- 
vidually by  a neurileme,  are  collected  into  fasciculi,  which,  in  that 
state,  have  a neurileme,  and  these  fasciculi  are  grouped  into  larger 
chords  or  nerves  proper.  The  elementary  tubes,  though  they  pass 
from  one  fasciculus  to  another,  do  not  discharge  or  empty  into  one 
another,  their  anastomosis  being  merely  one  of  adhesion.  These 
cylindrical  tubes  exist  chiefly  in  the  nerves. 

* Memoir  of  1833-36  to  the  Academy  of  Sciences  of  Berlin,  translated  by 
David  Craigie,  M.  D.  Edin.  Med.  and  Surg.  Journ.  Oct.  1837  : copied  into 
Essays  on  Physiology,  Phila.  1838„ 


352 


NERVOUS  SYSTEM, 


3.  A granulated  matter,  some  of  the  grains  of  which  are  very  fine 
and  some  coarser,  being  disseminated  through  the  others. 

This  is  confined  to  the  cineritious  substance  of  the  convolutions  of 
the  cerebrum,  to  the  laminated  surface  of  the  cerebellum,  and  to  the 
cineritious  part  of  the  Spinal  Marrow. 

4.  The  articulated  tubes  present  patulous  ends  to  this  granulated 
collection,  which  ends  are  fitted  for  the  purpose  of  receiving  them 
directly,  and  for  the  distillation  of  the  Nervous  fluid,  (Liquor  Ner- 
vosus.) 

5.  The  cylindrical  tubes  of  the  motiferous  nerves  are  immediate 
continuations  of  the  nodulated  tubes.  This  is  perceptible  in  the 
nerves  of  the  medulla  spinalis  and  of  the  cerebrum,  excepting  the 
Olfactory,  the  Optic,  and  the  Auditory  Nerves,  which  are  unchanged 
nodulated  tubes. 

6.  Professor  Ehrenberg’s  observations  on  living  nerves  have  not 
yet  exhibited  the  circulation  of  a nervous  fluid  in  them,  but  he  de- 
clares neither  for  nor  against  it. 

7.  The  Ganglions,  or  Nervous  knots,  consist  of  the  articulated 
tubes  alone,  or  mixed  with  the  cylindrical  tubes.  They  have  also 
a very  fine  net-work  of  blood  vessels,  with  nervous  granules  inter- 
mixed with  them.  They  are,  in  fact,  comparable  to  brains. 

The  Nervous  System  is  the  seat  of  intelligence,  and  also  extends 
its  physical  influence  to  every  part  of  the  body.  Both  the  one  and 
the  other  qualities  reside  in  its  central  portion:  the  first  in  the  brain, 
and  the  second  in  the  spinal  marrow.  When  the  communication 
between  the  brain  and  the  spinal  marrow  is  interrupted  by  an  acci- 
dent, or  in  an  experiment,  the  difference  between  the  influence  of 
the  two  is  strongly  marked:*  the  influence  of  the  brain  seeming  to 
be  entirely  intellectual,  so  that  an  animal  will  even  bear  its  removal 
without  immediate  death ; while  the  influence  of  the  spinal  marrow 
is  so  indispensable  to  life,  that  its  destruction  is  followed  by  instan- 
taneous and  perfect  death. f Under  common  healthful  circumstances, 
however,  the  two  seem  to  exercise  a mixed  influence  on  all  parts  of 
the  body ; as,  for  example,  upon  the  reception  of  distressing  intelli- 
gence, the  stomach  ejects  its  contents,  or  refuses  to  receive  more ; 

* Legallois  on  the  Principle  of  Life. 

j-  Observ.  and  Exper.  on  the  Nervous  System,  by  W.  E.  Horner,  M.  D- 
See  Chapman’s  Med.  and  Phys.  Journal,  vol.  i.  p.  285. 


INFLUENCE  OF  THE  NERVOUS  SYSTEM. 


353 


alarming  intelligence  causes  the  heart  to  flutter  and  to  palpitate,  and 
both  the  bladder  and  the  intestines  to  evacuate  their  contents.  On 
the  contrary,  a proper  degree  of  corporeal  exertion  strengthens  the 
intellectual  operations,  while  its  excess  debilitates  them.  That  these 
several  nervous  influences  are  seated  in  the  central  part  of  the  ner- 
vous system,  seems  proved  by  the  fact ; that  where  there  has  been  a 
congenital  deficiency  of  all  the  limbs,  or  an  accidental  one,  which, 
of  course,  removes  a very  considerable  portion  of  the  peripheral  part 
of  the  nervous  system  ; animal  life  and  the  intellectual  operations  have 
still  gone  on  vigorously. 

The  following  are  some  of  the  physical  functions  over  which  the 
nervous  system  seems  to  preside. 

Digestion ; the  whole  alimentary  canal,  from  the  mouth  to  the 
anus,  is  under  its  influence : first  of  all  in  mastication,  then  in  swal- 
lowing, afterwards  in  digestion  and  the  absorption  of  chyle,  and 
finally,  the  passing  of  the  effete  matter  out  of  the  body.  It  has 
been  sufficiently  proved,  by  the  experiments  of  several  physiologists, 
that  the  section  of  the  par  vagum  destroys  the  faculty  of  digestion. 

Respiration ; the  mechanical  act  of  this  process,  that  by  which  the 
cavity  of  the  thorax  is  enlarged  so  as  to  admit  of  the  introduction  of 
air,  evidently  depends  upon  the  phrenic  and  the  intercostal  nerves. 
If  the  nerves  which  supply  the  structure  of  the  lungs  be  alone  inter- 
cepted, as  the  par  vagum,  either  by  ligature  or  section,  the  changes 
on  the  blood  produced  by  respiration  cease,  and  the  animal  dies. 

Secretion,  exhalation,  absorption,  and  animal  heat,  seem  also  to 
be  dependent  upon  the  integrity  and  the  activity  of  nervous  influence. 
The  action  of  the  heart,  sensation  and  voluntary  motion,  are  in  the 
same  predicament. 

The  manner  in  which  these  several  kinds  of  innervation  is  pro- 
duced, is  unintelligible.  One  has  supposed  it  to  consist  in  a vibra- 
tion of  the  elementary  fibres  of  the  nerves ; another  in  an  agitation 
of  their  elastic  globules ; another  in  the  transmission  of  an  imponde- 
rable fluid,  as  ether,  magnetism,  electricity,  and  Galvanism.  Reil 
has  proposed,  on  this  subject,  what  has  been  termed  a chemico-vital 
hypothesis : according  to  him,  the  general  action  of  parts  depends 
upon  their  form  and  composition  ; consequently,  when  the  two  latter 
vary,  the  first  does  also.  M.  Beclard*  inclines  to  the  opinion,  that 
“the  nervous  system  is  the  elaborator  and  conductor  of  an  impon- 


Vol.  II.— 31 


* Anat.  Gen. 


354 


NERVOUS  SYSTEM. 


derable  agent ; and,  like  electricity  or  magnetism,  that  by  it  we  can 
explain  all  the  phenomena  of  innervation: — The  relation  between 
the  benumbing  influence  of  electric  fish  and  Galvanic  phenomena 
on  one  part,  and  ordinary  nervous  action  on  the  other ; — The  prac- 
ticability of  causing  Galvanic  phenomena  by  the  nerves  and  muscles 
alone; — The  possibility  of  producing  muscular  contraction,  the  chy- 
mifiant  action  of  the  stomach,  the  respiratory  action  of  the  lung,  & c., 
in  substituting  a Galvanic  for  a nervous  influence ; — The  existence 
of  a nervous  atmosphere,  acting  at  a distance  around  the  nerves  and 
muscles,  and  between  the  ends  of  divided  nerves; — The  wrinkling 
of  muscular  fibres  in  contraction,  and  the  relation  of  the  finest  trans- 
verse nervous  fibres  with  those  wrinkles:  are  phenomena  of  innerva- 
tion which  nearly  approach  certain  electro-magnetical  ones.” 

This  subtile  fluid,  according  to  M.  Beclard,  seems  to  be  formed 
every  where,  but  principally  in  places  where  there  is  much  vascu- 
larity along  with  the  ash-coloured  substance.  It  impregnates  all  the 
humours  and  organs.  The  blood  seems  to  be  especially  endowed 
with  it,  and  owes  to  it  the  properties  which  distinguish  it  during  life. 
In  consequence  of  which,  life  is  essentially  connected  with  the  re- 
ciprocal action  of  the  blood  upon  the  nervous  substance,  and  of  the 
nervous  substance  upon  the  blood.* 

Sir  Charles  Bell,  of  London,  has  presented,  in  a very  interesting 
light,  certain  functions  of  the  nervous  system  :f  by  his  researches  it 
appears,  that  besides  the  nerves  of  vision,  smell,  and  hearing,  there 
are  four  other  systems,  having  different  functions,  and  extended 
through  the  whole  frame.  Those  of  Sensation  ; of  Voluntary  Mo- 
tion ; of  Respiratory  Motion ; and  nerves,  which  give  unity  to  the 
body  in  harmonizing  the  functions  of  nutrition,  growth,  and  decay, 
or  whatever  else  is  indispensable  to  animal  existence.^ 

According  to  this  theory,  the  several  filaments  of  a nerve  exercise 
one  or  the  other  function,  but  only  the  one  ; these  dissimilar  filaments, 
being  bound  up  in  the  same  fasciculus,  constitute  a nerve  or  fascis, 

* M.  Rolando  (Saggio  sulla  vera  struttura  del  cervello,  e sopra  le  funzioni 
del  sistema  nervoso,  1809,  Beclard,  p.  622,)  has  been  so  much  taken  with  the 
Galvanic  manifestations  of  the  nervous  system,  that  in  the  laminated  arrange- 
ment of  the  cerebellum,  he  has  only  seen  a modification  of  the  Voltaic  pile. 

j-  Exposition  of  the  Natural  System  of  the  Nerves  of  the  Human  Body. 
Philad.,  1825. 

f:  For  a farther  view  of  the  present  state  of  opinions  on  the  physiology 
of  the  Nervous  System,  see  Human  Physiology  by  Robley  Dunglison,  M.D. 
Professor,  &c.,  Muller’s  Physiol,  and  Carpenter’s  Physiol. 


DEVELOPMENT  OF  THE  NERVOUS  SYSTEM. 


355 


and  they  never  exchange  power  with  one  another ; their  anatomical 
differences,  however,  are  such,  as  not  to  make  obvious  one  kind  of 
filaments  from  the  others.  Several  columns  of  nervous  matter  form 
the  spinal  marrow,  six  in  all,  three  on  each  side ; the  anterior  for 
voluntary  motion,  the  posterior  for  sensation,  and  the  middle  for 
respiration ; and  it  is  probable  that  still  more  may  be  found  out. 
The  first  and  the  third  ascend  into  the  brain,  and  the  middle  stops 
short  in  the  medulla  oblongata;  hence,  the  function  of  respiration 
goes  on  so  long  as  the  medulla  oblongata  remains  entire.  These 
few  principles,  supported  by  several  experiments,  have  enabled  Mr. 
Bell  to  bring  forward  a system  of  no  small  importance,  on  the  ana- 
tomy and  physiology  of  the  nervous  system.* 

The  development  of  the  nervous  system  is  amongst  the  earliest 
processes  in  the  distinct  evolution  of  the  fcetal  organs. f At  the  end 
of  the  first  month,  when  the  head  is  a mere  swelling  of  one  end  of 
the  small  maggot-like  being,  the  brain  and  the  spinal  marrow  are 
not  by  any  means  distinct,  but  the  parts  being  transparent,  a limpid 
fluid  holds  their  place.  About  the  fifth  or  sixth  week,  the  embryo 
having  acquired  a length  of  five  or  six  lines,  the  rudiments  of  the 
brain  appear  as  vesicles  containing  a whitish  and  almost  diaphanous 
fluid,  while  the  spinal  marrow  represents  a long  canal  containing  the 
same,  and  communicating  with  the  cerebral  vesicles. 

In  the  early  part  of  the  third  month,  the  brain  and  spinal  marrow 
show  very  distinctly  the  rudiments  of  the  several  cavities,  elevations, 
and  fasciculi,  which  mark  their  subsequent  mechanical  arrangement 
of  surface;  and  from  this  period  it  is  no  longer  difficult  to  trace  the 
successive  development  of  each  part  to  the  degree  of  perfection 
which  it  has  at  the  time  of  birth. 

From  the  many  observations  made  by  Tiedemann  on  these  points, 
he  has  deduced  the  conclusion,  that  the  brain  is  produced  by  the 
superior  part  of  the  spinal  marrow ; that  is  to  say,  by  the  medulla 
oblongata,  which  grows  and  is  developed  for  the  purpose.  That 
this  is  proved,  in  the  extension  upwards  and  forwards  of  the  two 

* The  same  subject  was  taken  up,  in  an  inaugural  thesis,  by  a zealous  and 
intelligent  graduate  of  the  University,  now  dead  ; and,  by  a series  of  ingenious 
experiments,  seems  to  have  been  generally  proved  and  illustrated.  Remarks 
on  some  of  the  Nervous  Functions,  by  J.  P.  Hopkinson,  M.  D.,  in  Chapman’s 
Med.  and  Phys.  Journal,  1823,  vol.  vi.,  p.  240. 

f Anat.  du  Cerveau,  par.  F.  Tiedemann,  traduit  par  Jourdan,  Paris,  1823, 
Anat.  Comp,  du  Cerveau,  par.  E.  R.  A.  Serres,  Paris,  1824. 


356 


NERVOUS  SYSTEM. 


principal  fasciculi  of  the  spinal  marrow,  and  by  a canal  which  is 
found  in  the  spinal  marrow  of  the  foetus,  being  extended  to  the 
fourth,  and  even  to  the  third  ventricle  ; also,  by  the  cerebellum  pro- 
ceeding evidently  from  the  medulla  spinalis,  since  its  two  crura  may 
be  traced  growing  from  it,  and  subsequently  uniting  over  the  fourth 
ventricle,  so  as  to  form  the  especial  structure  of  the  cerebellum ; 
also,  by  the  tubercula  quadrigemina  being  derived  from  the  corpora 
olivaria  of  the  medulla  oblongata,  and  by  the  thalami  and  the 
corpora  striata  proceeding  from  the  corpora  pyramidalia,  and  finally, 
forming  the  hemispheres  of  the  cerebrum. 

In  addition  to  the  preceding  proofs,  comparative  anatomy  fur- 
nishes other  illustrations.  The  brain  becomes  more  and  more  com- 
plex as  one  ascends  from  fish  to  reptiles,  from  the  latter  to  birds, 
and  then  to  mammiferous  animals.  The  spinal  marrow  is  very 
voluminous  in  the  inferior  animals,  while  the  brain  only  forms  an 
appendix  to  it ; whereas  if  the  spinal  marrow  were  an  appendix  to 
the  brain,  we  ought  to  find  the  last  of  a prior  formation  in  fcetuses ; 
and  also  in  a perfect  state  in  the  lower  animals,  before  a medulla 
spinalis  could  be  observed.* 


The  exploration  of  the  anatomy  of  the  Nervous  System  with  the 
microscope  having  become  a very  favourite  pursuit ; for  an  expo- 
sition of  the  general  results  of  such  labours,  see  Progress  of  the 
Anatomy  and  Physiology  of  the  Nervous  System,  during  the  year 
1S36,  by  Professor  Muller,  of  Berlin. 


* Tiedemann,  loc.  cit.  p,  157. 


BOOR  IX, 


FART  IS, 

ON  TIE  SPECIAL  ANATOMY  OF  TIIE  CENTRAL  PORTION  OF  THE  NERVOUS 

SYSTEM. 


CHAPTER  I. 

Of  the  Spinal  Marrow  and  its  Membranes T 

The  Spinal  Marrow,  ( Medulla  Spinalis ) though  frequently  de- 
scribed after  the  brain,  as  a continuation  or  appendage  of  it,  has 
precedence,  as  seen,  both  in  the  period  of  its  formation  in  the  em- 
bryo, and  in  its  importance  to  the  functions  of  the  animal  system ; 
it  will,  consequently,  be  proper  to  give  it  that  priority  in  description 
to  which  its  natural  rank  entitles  it. 

It  is  placed  within  the  vertebral  cavity,  and  extends  from  the 
first  vertebra  of  the  neck  to  the  first  or  second  vertebra  of  the  loins, 
inclusively.  It  is  surrounded  by  three  membranes,  of  which  the 
Dura  Mater  is  external,  the  Pia  Mater  internal,  and  the  Tunica 
Arachnoidea  between  the  other  two. 


SECT.  I. — MEMBRANES  OF  THE  SPINAL  MARROW 

Of  the  Dura  Mater  of  the  Medulla  Spinalis. 

This  membrane,  forming  the  exterior  envelope  of  the  spinal 
marrow,  extends  from  one  end  of  the  spinal  canal  to  the  other,  being 

* Anat.  Atlas,  Figs.  509  to  520  inclusive. 

31  * 


358 


NERVOUS  SYSTEM. 


continuous  above  with  the  dura  mater  of  the  brain,  and  terminating 
below  in  a cul-de-sac,  or  closed  extremity,  sending  off  branches 
corresponding  with  the  several  nerves.  It  does  not  adhere  to 
the  surface  of  the  spinal  canal,  but  lies  loosely  attached  to  it, 
with  the  exception  of  the  first  cervical  vertebra,  to  which  it  is  closely 
fastened.  Between  it,  and  the  ligaments  and  periosteum ’on  this 
surface  of  the  bones  of  the  spine,  is  a long,  loose,  and  spare  cellular 
substance,  generally  somewhat  watery,  and  containing  in  the  lum- 
bar and  sacral  regions,  a reddish,  adipose  matter. 

This  membrane  is  so  much  larger  than  the  medulla  spinalis,  that 
it  invests  it  very  loosely  and  always  presents  a collapsed  appearance. 
Where  the  nerves  penetrate,  it  furnishes  to  each  one,  a sheath  as  far 
as  the  intervertebral  foramen.  Having  reached  the  intervertebral 
foramen,  the  sheath  then  enlarges  so  as  to  enclose  the  ganglion,  ad- 
heres by  cellular  substance  to  the  contiguous  periosteum,  and  is  then 
insensibly  lost  in  the  tunics  of  the  nervous  trunk.  Those  sheaths 
are  longer  for  the  cauda  equina  than  elsewhere,  and,  of  course, 
observe  the  same  successive  obliquity  with  the  nerves  to  which  they 
belong. 

The  internal  surface  of  the  dura  mater  is  smooth  and  shining, 
which  is  owing  to  the  tunica  arachnoidea  being  reflected  over  it. 

This  membrane  has  a fibrous  texture,  and  with  inconsiderable 
exceptions,  is  like  that  of  the  brain. 

Of  the  Tunica  Arachnoidea  of  the  Medulla  Spinalis. 

This  membrane  is  next  to  the  dura  mater,  and  is  easily  distin- 
guished by  its  extreme  delicacy,  thinness,  and  almost  perfect  trans- 
parency. It  is  destitute  of  red  blood  vessels.  It  forms  a complete 
envelope  for  the  medulla  spinalis,  and  adheres  to  the  Pia  Mater 
very  loosely  by  means  of  long,  slender,  and  scattered  filaments  of 
cellular  substance.  If  the  dura  mater  be  slit  up  its  whole  length  be- 
fore and  behind,  and  a blow-pipe  be  introduced  at  one  end  of  the 
medulla,  between  the  pia  mater  and  the  arachnoidea,  inflation  will 
cause  the  latter  to  rise  ; and  to  present  itself  as  a long  capacious 
tube,  detaching  on  each  side  processes  which  surround  the  roots  of 
the  nerves.  These  processes  having  reached  the  points  where  the 
nerves  penetrate  the  dura  mater,  are  then  reflected  upon  its  internal 
face,  being  spread  over  it,  and  thus  give  it  the  glistening  appearance.. 


MEMBRANES  OF  THE  SPINAL  MARROW. 


359 


The  processes  enclosing  the  fasciculi  «f  the  spinal  nerves,  are  par- 
ticularly conspicuous  about  the  Cauda  Equina. 


Of  the  Via  Mater  of  the  Medulla  Spinalis. 

This  third  envelope  of  the  spinal  marrow  forms  also  a complete 
investment  of  the  latter,  and  adheres  very  closely  to  it.  Its  external 
face  is  smooth,  and  is  in  contact  with  the  arachnoidea,  from  which 
it  may  be  readily  separated  by  inflating  the  latter.  But  from  the 
middle  of  its  internal  face  both  anteriorly  and  posteriorly,  a process 
or  partition  penetrates  into  the  middle  fissures  of  the  medulla  spinalis, 
and  reaches  to  their  bottom.  From  these  partitions  there  proceeds 
a great  number  of  small  vascular  canals,  which  pass  in  various  di- 
rections through  the  medulla,  and  anastomose  freely  with  each  other. 
This  arrangement  is  rendered  sufficiently  obvious  by  injecting  the 
blood  vessels,  and  then  destroying  the  medulla  in  an  alkaline  solu- 
tion : or  if  the  medulla  be  hardened  by  neutral  salts  or  acids,  it  splits 
into  manyTongitudinal  radiated  laminae,  divisible  into  cords,  w'here- 
by  the  arrangement  Is  made  equally  manifest.  A fact  of  some  con- 
sequence is  thus  established,  to  wit,  the  similitude  between  the 
structure  of  a nerve  and  of  the  medulla  spinalis. 

At  the  inferior  end  of  the  medulla  the  pia  mater  becomes  a single 
cord,  which  is  continued  among  the  cluster  of  nerves  constituting 
the  Cauda  Equina  to  the  lower  end  of  the  tube  formed  by  the  dura 
mater,  and  there  it  joins  with  the  latter.  As  a membrane,  the  pia 
mater  is  much  more  complete  than  the  corresponding  one  of  the 
brain,  has  more  strength,  but  is  not  so  vascular.  Its  thickness  in- 
creases in  its  descent.  It  is  of  a yellowish- white  colour.  It  seems 
to  hold  the  medulla  somewhat  in  a state  of  compression,  for  when  a 
puncture  is  made  through  it,  the  medullary  substance  protrudes  like 
a hernia.  It  goes  from  the  medulla  to  the  fasciculi  of  nerves  and 
forms  their  neurileme  or  sheath. 

The  pia  mater  seems  to  impart  great  elasticity  to  the  spinal  mar- 
row, for  when  the  latter  is  detached  from  the  spine  by  the  severance 
of  its  nerves;  it  contracts  suddenly  and  forcibly,  to  the  amount  of 
from  one  to  two  inches. 


360 


NERVOUS  SYSTEM. 


SECT.  II. — OF  THE  SPINAL  MARROW. 

Its  general  form  is  cylindrical,  yet  it  has  slightly  the  appearance 
of  being  flattened  both  behind  and  before.  It  departs  also  from  the 
strict  cylindrical  shape,  by  being  enlarged  or  swollen  at  particular 
points.  One  of  these  enlargements  occurs  in  the  neck,  where  the 
spinal  canal  is  formed  by  the  five  lower  cervical  vertebrae,  and  the 
roots  of  the  axillary  plexus  of  nerves  are  given  off.  The  enlarge- 
ment is  in  the  transverse  direction  or  axis  of  the  spinal  marrow,  but 
not  so  much  in  its  thickness,  and  terminates  gradually  both  above 
and  below.  The  medulla  spinalis  afterwards  continues  small,  with 
very  slight  undulations  or  nodosities,  until  within  three  or  four  inches 
of  its  lower  extremity,  when  it  again  enlarges.  The  enlargement 
here,  though  sufficiently  obvious,  is  not  equal  in  actual  magnitude  to 
that  in  the  neck,  and  is  the  place  from  which  all  the  lumbar  nerves 
and  the  three  superior  sacral  proceed.  It  is  then  brought  gradually 
to  a point  somewhat  blunted,  which  most  commonly  does  not  descend 
below  the  first  lumbar  vertebrae.*  The  point  is,  in  some  rare  cases, 
bifurcated,  and  by  a transverse  fissure  above  it  converted  into  a 
tubercle. 

The  spinal  marrow,  besides  terminating  so  much  above  the  lower 
end  of  the  spinal  canal,  is  much  smaller  in  its  diameter,  even  with 
the  addition  of  its  membranes,  than  the  canal.  This  circumstance 
prevails,  especially  in  the  neck,  and  in  the  loins,  where  much  motion 
is  experienced;  and,  consequently,  a provision  is  thus  made  against 
any  injury  to  it  from  pressure. 

The  Medulla  Spinalis  is  marked  off,  longitudinally,  into  two  sym- 
metrical parts,  by  one  fissure  in  front  and  another  behind,  both  of 
which  extend  its  whole  length,  and  are  placed  exactly  in  its  middle. 
The  contiguous  edges  or  surfaces  of  each  of  these  fissures  adhere  so, 
that  it  requires  a slight  maceration  or  dissection  to  render  them  evi- 
dent. The  posterior  fissure  is  decidedly  deeper,  especially  at  its 
upper  part,  than  the  anterior:  but  the  latter,  in  return,  is  somewhat 
broader.  The  difference  in  depth,  however,  is  unimportant,  as  sub- 
jects are  frequently  met  with  in  which  it  is  not  appreciable. 

* The  Spinal  Marrow  at  the  third  month  of  the  embryo  extends  to  the  end 
of  the  coccyx  ; it  then  suddenly  contracts  to  the  second  lumbar  vertebra.  The 
coccyx  is  cotemporaneously  reduced  from  seven  to  four  pieces.  Serres.. 


SPINAL  MARROW. 


3C1 


Moreover,  on  each  side  of  the  medulla  spinalis  there  is  a lateral 
fissure.  It  is  not  precisely  in  the  middle,  but  somewhat  posterior, 
and  penetrates  inwards  and  forwards.  In  many  instances  it  is 
merely  a simple  superficial  depression,  much  less  deep  than  either 
of  the  former.  It  does  not  run  the  whole  length  of  the  medulla 
spinalis,  but  terminates  somewhere  in  the  upper  part  of  its  thoracic 
portion  by  joining  with  its  fellow  after  having  converged  regularly 
towards  it.*  The  different  opinions  of  anatomists  on  the  existence 
of  this  fissure  may  be  accounted  for  by  its  being  readily  found  in 
early  life,  while  it  is  obliterated  or  very  indistinct  in  old  age.  This 
lateral  fissure  should  be  carefully  distinguished  from  two  others,  one 
before  and  the  other  behind  it,  which  extend  the  whole  length  of 
the  medulla  spinalis,  and  consist  in  a series  of  little  depressions, 
running  into  each  other  and  transmitting  the  filaments  which  form 
the  roots  of  the  spinal  nerves.  The  posterior,  of  the  last  named 
lateral  fissure,  is  deeper  than  the  anterior,  and  penetrates  in  the 
same  direction  with  the  lateral  fissure  first  mentioned  ; it  also,  in 
like  manner,  joins  its  fellow,  but  only  after  having  proceeded  to 
within  a few  lines  of  the  inferior  end  of  the  medulla  spinalis. 

The  substance  of  the  spinal  marrow  being  of  two  kinds,  cineri- 
tious  and  medullary,  the  order  of  their  position  is  reversed  from 
what  occurs  in  the  brain  ; for  the  cineritious  is  included  or  enveloped 
by  the  other.  On  making  a transverse  section,  the  cineritious  will 
be  found  much  less  abundant  than  the  other,  and  consisting  of 
a thin  transverse  vertical  lamina  in  or  near  the  centre  of  the  me- 
dulla: this  part  is  joined  at  either  end  to  a portion  somewhat  cres- 
centic, whose  concavity  is  outwards,  and  the  convexity  inwards. 
The  transverse  part  does  not  run  into  the  middle  of  the  crescent,  but 
somewhat  anterior  to  the  middle,  so  that  the  anterior  horn  is  shorter 
than  the  other,  and  is  also  thicker  and  obviously  more  obtuse.  The 
cineritious  or  grayish  substance  is  more  abundant  at  the  lower  part 
of  the  medulla  spinalis  than  it  is  above.  In  the  foetus,  at  the  end  of 
gestation,  it  predominates  below,  occasionally,  to  the  entire  exclu- 
sion of  the  other.  Rolando  asserts  that  in  the  spinal  cord  there  are 
two  kinds  of  cineritious  matter,  the  one  commonly  acknowledged 
and  which  he  calls  cinerea  vasculosa  ; the  other  at  the  posterior  horn 
of  the  cineritious  crescent,  is  said  by  him  to  be  perfectly  gray,  and 
which  he  calls  cinerea  gelatinosa,  being  asserted  to  contain  corpuscles 


* Meckel,  Manuel  D’Analomie. 


362 


NERVOUS  SYSTEM. 


similar  to  the  red  particles  of  frog’s  blood.  The  medullary  or  white 
substance  is  more  abundant  laterally  than  elsewhere,  and  has  its  two 
symmetrical  sides  joined  together  by  a thin  lamina  at  the  bottom  of 
the  anterior  and  the  posterior  fissure. 

Each  half  or  symmetrical  side  of  the  medulla  spinalis  is  itself 
divided  into  two  cords,  marked  off  from  each  other  by  the  poste- 
rior horn  of  the  cineritious  crescent,  and  by  the  first  described  lateral 
fissure.  Of  these  cords  the  anterior  is,  consequently,  much  the 
larger  ; it  is  also  longer  and  forms  the  inferior  extremity  or  the  point 
of  the  medulla  spinalis.  The  posterior  cord,  though  so  much 
smaller  and  narrower  than  the  anterior,  is  itself  subdivided  into  two, 
by  a slight  but  well  marked  split ; of  these  last  two  cords,  the  one 
next  to  the  posterior  middle  fissure  of  the  medulla  is  smaller  than 
the  other.  These  arrangements  according  to  Meckel,  are  much 
more  obvious  in  the  early  life  of  the  human  subject,  than  afterwards  ; 
and  are  particularly  conspicuous  in  the  brute  creation. 

The  thin  white  laminse  by  which  the  two  sides  of  the  spinal  mar- 
row adhere  to  each  other  at  the  bottom  of  the  middle  fissures,  are 
called,  by  modern  anatomists,  Anterior  and  Posterior  Commissures. 
Their  precise  arrangement  is  not  yet  fully  ascertained,  but  it  is  stated 
by  Gall  and  Spurzheim,*  that  the  Anterior  Commissure  is  formed 
by  transverse  fibres  or  filaments,  which  adhere  to  one  another  from  the 
opposite  sides  like  a suture,  or  after  a serrated  fashion  ; whereas, 
the  Posterior  Commissure  is  formed  by  a band  of  longitudinal  fibres. 
There  is  also  another  Commissure,  called  Middle  or  Cortical,  from 
its  position,  and  from  its  being  formed  out  of  the  transverse  part  of 
the  grayish  or  cineritious  substance. 

The  cords  which  form  each  half  of  the  medulla  are  differently 
disposed : the  posterior  continues  on  the  side  to  wdiich  it  specially 
belongs,  while  the  anterior  having  got  within  the  circumference  of 
the  first  cervical  vertebra,  crosses  over  to  the  opposite  side  by  de- 
cussating with  its  fellow.  This  decussation  occupies  the  space  of 
four  or  five  lines,  and  interrupts,  for  that  distance,  the  middle  fissure 
in  front  of  the  medulla.  It  is  not  effected  by  the  cords  passing  in 
mass  from  one  side  to  the  other,  but  each  cord  sends  off  four  or 
five  fasciculi,  which  are  interwoven  with  their  congeners,  like  the 
fingers  of  the  two  hands  when  interlocked  obliquely.  It  is  to  be 
observed  that  the  whole  mass  of  the  anterior  cords  is  not  subjected 


Recherches  sur  la  Syst.  Nerv.  et  sur  celu,  du  Ccrveau.  Paris,  1803. 


SPINAL  MARROW. 


363 


to  such  distribution  ; for  the  fasciculi  just  described  come  from  their 
anterior  and  from  their  posterior  faces,  while  the  intermediate  part 
is  permitted  to  pursue  its  course  straight  upwards.  This  decussa- 
tion, upon  which  so  much  interesting  physiological  speculation  de- 
pends, has  been  known  for  the  last  century  or  more,  and  is  spoken 
of  by  Mistichelli  and  Petit.  There  are  other  places  where  the  fasci- 
culi of  the  spinal  marrow  seem  to  cross  from  one  side  to  the  other, 
but  the  fact  is  not  yet  verified  sufficiently. 

The  existence  of  canals  in  the  spinal  marrow  has  been  from  time 
to  time  announced  ;*  though  authors  differ  much  in  the  accounts  of 
their  position  and  extent.  When  such  an  appearance  is  presented, 
it  is  supposed,  by  some,  to  be  either  the  result  of  disease  or  of  acci- 
dent, wfith  the  exception  of  a small  one  of  eight  or  nine  lines  long, 
which  communicates  at  one  end  with  the  fourth  ventricle,  and  is 
shut  up  at  the  other. f 

The  central  ends  of  the  spinal  nerves,  according  to  Valentin,  do 
not  terminate  with  the  spinal  cord,  but  having  joined  it,  ascend  into 
the  brain.  The  nerves  below  ascend  directly  upwards,  but  the 
higher  ones  pass  inwards  towards  the  centre  of  the  cord  almost  to 
the  gray  substance,  and  are  then  directed  upwards  to  the  brain.  In 
the  white  substance  of  the  medulla  spinalis,  the  nervous  fibres  are 
in  contact,  but  upon  the  borders  of  the  gray  substance,  they  are  in- 
termixed with  its  globules.  Being  subsequently  dispersed  in  the 
brain,  they  form  loops  in  the  cortical  substance  and  terminate  in  that 
way  by  mutual  junction.^ 

The  spinal  marrow  of  a child,  is  very  easy  to  divide  by  tearing  it 
into  threads,  running  its  whole  length  ; these  threads  do  not  seem 
to  have  any  determinate  number,  but  to  be  regulated  by  the  healthy 
consistence  of  the  spinal  marrow,  and  the  patience  with  which  the 
process  is  pursued.  If  a spinal  marrow  has  been  macerated  for 
some  years  in  spirits,  it  may  be  broken  or  split  up  into  radii,  or 
segments,  running  from  the  centre  to  the  circumference,  like  a tree, 
and  these  sections  divided  into  thin,  short,  flat  laminae  adhering 
to,  or  anastomosing  with  such  as  are  contiguous  to  them.  Midler 
found  a similar  arrangement  in  the  spinal  marrow  of  the  Petromyzon 
Marinus,  though  he  has  never  seen  it  in  any  other  animal. 

* Gall,  Portal,  Morgagni.  f Meckel,  p.  605,  vol.  ii.  Bichat,  vol.  iii.  p.  128. 

t Muller,  p.  655. 


364 


NERVOUS  SYSTEM. 


The  Spinal  Marrow  sends  out  from  its  sides  thirty  pairs  of  nerves, 
which,  like  the  vertebrae,  are  arranged  into  cervical,  dorsal  or  tho- 
racic, lumbar  and  sacral.  Of  these  there  are  eight  cervical,  one  of 
which,  from  its  escaping  between  the  occiput  and  the  first  vertebra, 
is  most  usually  designated  as  sub-occipital ; and,  therefore,  the  num- 
ber of  the  cervical  nerves  is  reduced  to  the  same  with  that  of  the 
vertebrae  to  wit,  seven.  There  are  twelve  pairs  of  dorsal  nerves, 
five  of  lumbar,  and  five  of  sacral.  Occasionally,  there  is  a sixth 
sacral  nerve  on  each  side,  which  augments  the  number  of  spinal 
nerves  to  thirty-one  pairs. 

Every  spinal  nerve  is  formed  from  two  roots  on  the  same  level, 
one  before  and  the  other  behind,  and  each  root  consists  in  several 
fasciculi  of  nervous  matter.  The  front  root  arises  from  the  ante- 
rior cord  of  the  medulla  spinalis,  and  the  other  from  the  posterior 
cord.  The  posterior  root  is  larger  than  the  anterior,  but  has  fewer 
fasciculi  in  its  composition,  and  is  not  so  filamentous.  The  two  roots 
are  kept  asunder  by  the  Ligamentum  Denticulatum.  The  fasciculi 
of  each  are  slightly  connected  by  a loose  delicate  cellular  substance,  and 
as  they  are  about  penetrating  the  dura  mater,  each  fasciculus  collects 
into  a single  cord,  which  passes  the  dura  mater  through  its  appro- 
priate foramen.  In  this  way  the  anterior  and  posterior  roots  are 
kept  distinct  till  they  have  got  to  the  outside  of  the  membrane  men- 
tioned ; but  the  foramina,  through  which  they  pass,  border  closely 
upon  one  another.  The  posterior  root,  then  forms  a ganglion  of  a 
round  or  oval  shape ; from  whose  external  extremity  there  proceeds 
a single  nervous  trunk,  which  is  joined  immediately  at  its  com- 
mencement by  the  anterior  root. 

With  the  exception  of  the  ganglions  of  the  sacrum,  which  are  in 
the  spinal  cavity  of  that  bone,  these  bodies  are  placed  in  the  interverte- 
bral foramina.  The  size  of  the  ganglion  is  generally  proportionate 
to  that  of  the  nerve  from  which  it  proceeds,  but  not  invariably  so, 
as  some  of  the  sacral  ganglions  are  in  small  excess  over  the  size  of 
their  nerves. 

The  two  nerves  of  the  same  pair,  though  generally  symmetrical, 
or  precisely  resembling,  are  not  constantly  so ; sometimes  one  is  placed 
higher  than  the  other,  and  the  number  of  the  fasciculi  may  be  greater  or 
less.  The  roots  of  the  nerves  are  much  nearer,  or  cluster  more 
at  the  extremities  of  the  spinal  marrow,  than  at  its  middle. 

The  Cervical  Pairs  of  Nerves  are  nearly  horizontal  in  their  course 


SPINAL  MARROW. 


365 


from  the  medulla  spinalis  to  the  foramina  in  the  dura  mater.  The 
first  one,  or  the  sub-occipital,  is  strictly  so ; the  others  incline 
very  gradually  more  and  more  downwards.  They  have,  therefore, 
but  a very  short  passage  before  they  reach  the  intervertebral  fora- 
mina. Their  roots  are  so  pyramidal,  that  the  bases  nearly  touch  each 
other,  and,  for  the  most  part  are  connected  by  an  anastomosing  fila- 
ment, which  goes  from  the  upper  margin  of  the  nerve  below, 
to  the  lower  margin  of  the  nerve  above.  These  anastomoses  con- 
necting the  lower  fasciculi  with  the  upper,  are  both  on  the  anterior 
and  posterior  cords  of  the  medulla,  but  more  uniformly  as  regards 
the  latter.  Modifications  of  this  arrangement,  which  it  is  unneces* 
sary  to  specify,  are  met  with  in  different  subjects. 

The  Dorsal,  or  Thoracic  Pairs  are  much  inferior  in  size  to  any 
'Other  nerves,  exeept  the  inferior  sacral.  Anastomosing  filaments  do 
not  generally  prevail,  yet  they  are  found  occasionally,  as  in  the  neck, 
upon  the  two  or  three  upper  pairs.  The  first  one  has  the  broad  py- 
ramidal or  triangular  root  of  a cervical  nerve,  and  resembles  it  also  in 
volume.  The  second  is  the  smallest  of  any ; they  then  go  on  increasing 
in  size  to  the  lowest,  but  not  in  uniform  gradation.  They  are  suc- 
cessively more  oblique,  and  consequently  longer  from  their  bases  to 
their  passage  through  the  dura  mater. 

The  Lumbar  and  the  Sacral  Pairs  arise  closely  upon  each  other, 
indeed  in  absolute  contact  successively,  from  the  lower  end  of  the 
medulla  spinalis,  and  form  a cluster  of  filaments  resembling  the  tail 
of  a horse,  hence  it  is  called  Cauda  Equina.  As  their  place  of 
origin  is  within  the  precincts  of  the  first  lumbar  vertebra  and  the 
two  or  three  last  dorsal,  they  all  observe  a very  descending  course 
in  their  progress  to  the  inter-vertebral  foramina,  and  the  lower  ones  are 
almost  vertical.  Notwithstanding  they  are  in  contact,  and  adhere 
by  a loose  cellular  substance,  yet  there  are  no  anastomosing  fila- 
ments between  the  adjacent  roots.  From  the  sacral  ganglions  pre- 
senting the  peculiarity  of  being  situated  in  the  spinal  cavity  of  the 
sacrum,  instead  of  in  the  foramina,  the  single  nerve  formed  from  the 
ganglion  and  the  "anterior  fasciculus,  has  to  proceed  a distance 
more  or  less  considerable  in  the  spinal  cavity  before  it  can  escape 
from  it. 


366 


NERVOUS  SYSTEM. 


Of  the  Ligamenta  Denticulata. 

These  bodies  are  narrow  semi-transparent  bands  and  very  thin, 
which  are  placed  one  on  either  side  of  the  medulla  spinalis,  between 
the  pia  mater  and  the  tunica  arachnoidea.  They  commence  at  the 
occipital  foramen,  by  an  adhesion  to  the  dura  mater,  and  descend- 
ing between  the  anterior  and  the  posterior  fasciculi  of  the  roots  of 
the  nerves,  terminate  somewhat  above  the  inferior  extremity  of  the 
medulla  spinalis. 

Each  one  is,  at  its  commencement,  in  front  of  the  accessory 
nerve,  and  in  descending  is  rather  nearer  to  the  posterior  than  to 
the  anterior  fasciculi.  By  its  internal  margin  it  adheres  with  a uni- 
formity somewhat  interrupted  by  fissures  to  the  pia  mater,  but  the 
external  margin  has  a very  different  arrangement ; for  it  sends  off 
at  intervals  from  twelve  to  twenty-four  serrated  or  denticulated  pro- 
cesses, which  for  the  most  part  are  placed  between  the  fasciculi  of 
cervical  and  of  dorsal  nerves.  The  extremities  of  these  teeth  are 
small,  rounded  and  strong,  are  surrounded  by  the  arachnoidea,  and 
adhere  very  firmly  to  the  dura  mater,  being  pointed  downwards. 
The  position  and  connexions  of  each  ligamentum  denticulatum  are 
such  as  to  make  it  serve  as  a fastening;  which  use  is  additionally  in- 
dicated by  its  fibrous  texture,  and  by  the  necessity  that  the  medulla 
spinalis  has  for  such  fastening,  in  consideration  of  its  being  so  deficient 
in  filling  up  the  vertebral  canal.* 

It  is  taught  by  many  'anatomists,  that  the  ligamenta  denticulata, 
from  the  opposite  sides,  join  at  the  lower  end  of  the  spinal  marrow 
to  form  the  single  cylindrical  cord,  that  passes  thence  to  the  lower 
end  of  the  spinal  cavity,  and  has  been  described  as  an  emanation 
from  the  pia  mater.  I am,  however,  induced  to  think  with  Meckel 
and  others,  that  general  analogy  is  in  favour  of  the  latter. 

* An  opinion  has  been  advanced  by  Professor  Pancoast  that  the  pia  mater  of  the 
elephant,  of  the  bullock,  and  of  man,  forms  by  its  duplicature  the  ligamentum  deu- 
ticulatum.  The  specimen  of  the  former  which  I have  seen  in  his  possession  affords 
strong  indications  of  that  arrangement:  at  the  same  time,  in  examining  its  point  of 
origin  in  man  from  the  dura  mater  at  the  foramen  magnum,  its  distinctly  fascicu- 
lated and  tendinous  character  there,  is  in  opposition  to  this  conclusion  : the  fissures 
which  separate  it  along  its  internal  margin  from  the  pia  mater  are  also  not  favour- 
able to  this  idea,  which  in  other  respects  is  plausible  and  ingenious. — Wistar’s  Anat. 
Vol.  2,  p.  513.  Phila.,  1839. 


BLOOD  VESSELS  OF  THE  MEDULLA  SPINALIS. 


367 


SECT.  III. — OF  THE  BLOOD  VESSELS  OF  THE  MEDULLA 
SPINALIS. 

\ 

The  Arteries  of  the  Spinal  Marrow  are  derived  from  the  Verte- 
bral, Intercostal,  Lumbar,  and  Sacral  Arteries. 

1 . The  posterior  Spinal  Artery  ( Arteria  Spinalis  Posterior ) is  the 
lowest  branch  of  the  vertebral,  given  off  in  the  cavity  of  the  cranium. 
It  reaches  soon  after  its  origin,  the  posterior  face  of  the  Medulla 
Spinalis,  and  runs  to  the  lower  extremity  of  the  latter,  on  the  side 
of  its  posterior  fissure.  Its  course  is  parallel  with  its  fellow  and 
very  serpentine.  In  its  descent  it  is  continually  re-enforced  by 
small  branches  which  get  into  the  spinal  cavity  through  each  of  the 
intervertebral  foramina,  they  being  twigs  from  the  Vertebral,  Inter- 
costal, Lumbar  and  Sacral  Arteries. 

2.  The  Anterior  Spinal  Artery  ( Arteria  Spinalis  Anterior)  arises 
above  the  last  from  the  vertebral.  Shortly  after  its  origin  it  unites 
with  its  fellow  into  a common  trunk,  which  descends  along  the  an- 
terior fissure  of  the  medulla  spinalis,  but  is  subject  to  interruptions. 
It  also  is  re-enforced  by  twigs  from  the  same  arteries  that  pass 
into  the  spinal  cavity  through  the  intervertebral  foramina.  In  its 
whole  course  it  sends  off  branches  from  each  side  to  the  medulla 
spinalis. 

The  Cauda  Equina  is  supplied  by  arteries  from  the  Lumbar  and 
from  the  Sacral  Arteries  which  reach  it  through  the  foramina,  be- 
tween the  vertebrae  and  in  tire  sacrum. 

The  veins  of  the  Spinal  Marrow  are  very  abundant.  A large 
one  on  each  side  of  the  middle  line,  called  the  Sinus  Columme 
Vertebralis,  is  situated  in  the  spinal  cavity,  on  the  posterior  face 
of  the  bodies  of  the  vertebrae,  between  their  ligamentous  covering 
and  tire  dura  mater.  They  are  the  general  recipients  for  the  blood 
of  the  contiguous  structure.  They  detach  a considerable  number  of 
branches,  which  run  transversely,  and  anastomose  with  one  another 
on  the  body  of  each  vertebra,  so  that  each  vertebra  has  its  little  sys- 
tem of  anastomosing  branches.  These  junctions  constitute  the  Cir- 


368 


NERVOUS  SYSTEM. 


celli  "V'enosi.  These  anastomoses  communicate  with  the  intercostal 
veins,  and,  indeed,  with  all  such  as  are  on  the  outside  of  the  spinal 
column,  by  means  of  small  branches  that  get  out  by  the  interverte- 
bral foramina.  They  receive  the  veins  from  the  bodies  of  the  ver- 
brce,  and  from  the  dura  and  pia  mater  of  the  spinal  marrow. 

The  two  sinuses  may  be  traced  as  low  down  as  the  inferior  end 
of  the  sacrum,  where  they  arise  by  small  trunks  from  the  fatty  mat- 
ter which  surrounds  the  lower  end  of  the  cauda  equina.  When 
their  size  is  somewhat  augmented  by  their  ascent,  they  communi- 
cate by  a large  transverse  branch.  The  superior  end  of  each  sinus 
terminates  by  several  anastomoses  with  the  vertebral  vein,  and  with 
the  anterior  occipital  sinus:  through  the  latter  of  which  its  blood 
is  finally  carried  into  the  lateral  sinus.  For  a farther  account,  see 
Sinus  Vertebrales. 


CHAPTER  II. 


Of  the  Eli c c pit  alon,  or  Brain. 

By  this  term  is  designated  that  section  of  the  central  portion  of  the 
nervous  system,  which  is  contained  within  the  bones  of  the  cranium. 
In  its  general  configuration  it  differs  materially  from  the  medulla 
spinalis,  in  being  spheroidal  or  oval.  It  is  surrounded  by  the  same 
membranes;  to  wit,  the  Dura  Mater  externally,  the  Tunica  Arach- 
noidea  next,  and  the  Pia  Mater  internally. 

The  Encephalon  is  formed  by  cineritious  and  medullary  matter, 
and,  as  a mass,  consists  of  four  distinct  portions.  The  Medulla 
Oblongata,  which  is  a continuation  of  the  spinal  marrow,  or  its 
superior  part;  the  Protuberantia  Annularis,  or  Pons  Varolii,  which 
is  placed  at  the  upper  extremity  of  the  Medulla  Oblongata ; the 
Cerebrum,  which  occupies  six  or  seven-eighths  of  the  cavity  of  the 
cranium ; and  the  Cerebellum,  which  lies  upon  the  posterior  fossa? 
of  the  base  of  the  cranium.  As  the  brain  is  a double  organ,  each  of 


MEMBRANES  OF  THE  BRAIN. 


369 


these  parts  is  symmetrical,  or  consists  in  right  and  left  halves  per- 
fectly alike. 

SECT.  I. — OF  THE  MEMBRANES  OF  THE  BRAIN,  OR 
ENCEPHALON.* 

Of  the  Dura  Mater. 

This  membrane,  the  most  exterior  of  the  three  belonging  to  the 
encephalon,  lines  the  whole  internal  face  of  the  cavity  of  the  cra- 
nium, and  is  attached  with  great  tenacity  to  it,  particularly  in 
early  life,  from  which  cause  it  is  considered  also  as  an  internal  peri-, 
osteum. 

Its  external  surface  has  a rough  unequal  appearance,  and  adheres 
much  more  strongly  where  the  sutures  exist  than  on  the  other  sur- 
face of  the  bones,  owing  to  its  detaching  many  large  filaments, 
which  penetrate  into  the  sutures  and  reach  to  the  pericranium.  Its 
adhesion  to  the  surface  generally  of  the  bones  is  accomplished  by 
fine  filaments  of  fibres,  and  by  very  numerous  and  small  blood  ves- 
sels  which  become  evident  from  the  dots  of  blood  collected  upoti  it, 
when  the  bones  are  torn  up,  as  in  the  usual  manner  of  examining 
the  head.  To  the  base  of  the  cranium,  its  adhesion  is  still  stronger, 
owing  to  the  abundance  of  the  foramina  and  fissures  there ; to  the 
margin  of  each  one  of  the  foramina  it  is  fixed  with  extreme  com-. 
pactness,  and  may  be  considered  as  continuous  with  the  adjacent 
pericranium. 

The  external  surface  of  the  Dura  Mater  is  marked  by  the  arteries 
and  veins  which  creep  and  ramify  through  it,  and  make,  as  mem 
tioned  elsewhere,  corresponding  furrows  in  the  bones. 

The  Dura  Mater  consists  of  two  laminae,  one  within  the  other  ; 
they,  however,  are  attached  so  closely  in  the  greater  part  of  their  ex- 
tent, that  it  requires  the  knife,  or  strong  artificial  force,  to  separate 
them.  Sometimes  in  tearing  off  the  skull-cap  of  a middle-aged 
person,  the  external  lamina  is  brought  away  with  the  bone. 

Several  processes  arise  by  a duplicature  of  the  internal  lamina 


* Anat.  Atlas,  Figs.  522,  523  to  537,  inclusive. 


370 


NERVOUS  SYSTEM. 


of  the  dura  mater,  and  extend  from  the  circumference  towards  the 
centre  of  the  cavity  of  the  cranium.  They  are  as  follows : — 

The  Falx  Cerebri  separates  the  hemispheres  of  the  brain,  and  is 
consequently,  precisely  under  the  middle,  line  of  the  head.  Its 
shape  is  well  indicated  by  its  name.  It  commences  by  a small 
point  from  the  middle  of  the  body  of  the  sphenoid  bone,  and  con- 
tinues to  arise  along  the  crista  galli,  the  spine,  and  middle  line  of 
the  frontal  bone,  the  sagittal  suture  and  the  upper  limb  of  the  occi- 
pital cross,  till  it  reaches  the  internal  occipital  protuberance.  It  is 
about  an  inch  broad  in  front,  where  it  begins,  but  it  increases  con- 
tinually, though  gradually,  in  breadth  till  its  termination,  where  it 
is  two,  or  twTo  and  a half  inches  wide.  It  is  strongly  fastened  along 
the  crista  galli,  and  at  the  foramen  ccecum ; and  being  also  fastened 
behind  to  the  tentorium,  (with  which  it  is  continuous,)  as  well  as 
along  the  intermediate  points  of  bone,  it  is  kept  in  a state  of  strict 
tension,  which  does  not  admit  of- its  wavering  to  one  side  or  to 
the  other.  Its  inferior  margin  is  very  concave,  and  goes  to  wdthin  a 
small  distance  of  the  corpus  callosum.  There  are  sometimes  con- 
siderable apertures  in  it,  through  which  the  flat  surfaces  of  the  he- 
mispheres come  in  contact. 

The  Tentorium  Cerebelli,  another  process  of  the  internal  lamina 
of  the  dura  mater,  is  placed  transversely  across  the  posterior  part 
of  the  cranium,  and  separates  the  cerebellum  from  the  posterior 
lobes  of  the  cerebrum.  It  is  continuous  with  the  posterior  end  of 
the  falx  major,  whereby  these  two  processes  exercise  a mutual  ten- 
sion. The  tentorium  is,  therefore,  kept  convex  above  and  concave 
below. 

Its  form  is  crescentic ; its  outer  circumference  is  extended  along 
the  horizontal  limbs  of  the  occipital  cross,  and  along  the  superior 
angle  or  margin  of  the  petrous  bones  to  the  posterior  clinoid  pro- 
cess. The  internal  circumference  is  much  smaller  and  unattached, 
and  being  placed  immediately  behind  the  sella  turcica,  it  leaves  an 
opening  (the  Foramen  Ovale)  which  is  nearly  of  the  same  size  with, 
and  occupied  by  the  tuber  annulare  and  the  crura  cerebri.  The  an- 
terior extremities  of  the  crescent  are  continued  from  the  posterior 
clinoid  process  on  each  side,  to  the  anterior,  so  that  a deep  depres- 
sion is  formed  for  lodging  the  pituitary  gland. 


MEMBRANES  OF  THE  BRAIN. 


371 


The  Falx  Cerebelli  is  a small  triangular  process  of  the  dura 
mater,  "which  extends  in  the  middle  line  from  the  under  surface  of 
the  tentorium  to  the  posterior  margin  of  the  occipital  foramen.  Its 
base  is  above,  and  its  point  below  : the  latter  terminates  by  a small 
bifurcation.  It  adheres  by  its  posterior  margin  to  the  middle  infe- 
rior limb  of  the  occipital  cross  ; the  anterior  margin  is  free,  and 
serves  to  separate  the  two  hemispheres  of  the  cerebellum. 

The  Dura  Mater  is  essentially  fibrous,  as  is  sufficiently  evident  at 
whatever  point  it  may  be  examined.  These  fibres  have  no  settled 
course,  but  cross  each  other  in  every  direction.  It  is  white,  suffi- 
ciently transparent  for  the  vessels  of  the  pia  mater  to  be  imperfectly 
seen  through  it,  and  almost  inelastic.  Its  internal  face  is  smooth 
and  polished,  and  is  covered  or  lined  by  the  tunica  arachnoidea, 
the  halitus  from  which  gives  it  a slippery  feel.  It  is  insensible  to 
common  excitants,  such  as  cutting,  or  even  cauterizing  it;  from 
which  circumstance,  together  with  the  common  inability  of  anato- 
mists to  trace  nerves  into  its  structure,  it  is  supposed,  by  many,  to 
be  entirely  destitute  of  them.  The  learned  Chaussier,  however, 
takes  a different  position  in  regard  to  these  points,  and  says,  that  it 
has  sensibility,  and  that  though  none  of  the  cerebral  nerves  can  be 
traced  into  it,  yet,  by  attentive  examination,  it  is  found,  that  fila- 
ments from  the  sympathetic  nerve  follow  the  ramifications  of  its 
middle  or  great  artery.* 

It  is  well  supplied  with  blood  vessels,  both  arteries  and  veins. 
The  former  are  derived  principally  from  the  branches  of  the  internal 
maxillary  of  either  side,  which  get  into  the  cranium  through  the 
foramen  spinale  and  ovale  of  the  sphenoid  bone.  There  are  branches 
also  from  the  ethmoidal,  the  inferior  pharyngeal,  and  the  vertebral. 
The  branch  of  the  internal  maxillary  called  meningea  magna  divides 
into  two,  of  which  the  anterior  being  the  more  considerable,  gains  the 
anterior  and  inferior  angle  of  the  parietal  bone;  but  the  other  is  directed 
backwards  across  the  squamous  portion  of  the  temporal.  Each  of 
these  branches  is  subdivided  into  a considerable  number  of  smaller 
ones,  which  for  the  most  part  incline  backwards,  in  observing  the 
course  marked  out  by  the  furrows  on  the  flat  bones  of  the  cranium. 
When  the  ramifications  become  small  they  then  cease  to  impress  the 
bones.  Their  capillary  terminations  are  supposed  by  Bichat  to  be 


Exposition  de  L'Encephale,  p.  23. 


372 


NERVOUS  SYSTEM. 


in  small  number  comparatively,  and  to  be  limited  principally  to  those 
of  nutrition. 

Some  of  the  veins  accompany  the  arteries,  as  in  other  parts  of  the 
body,  and  empty  into  the  sinuses  about  the  base  of  the  cranium. 
In  the  case  of  both  arteries  and  veins,  there  are,  however,  very  fre- 
quent anastomoses  with  the  blood  vessels  of  the  diploic  structure  of 
the  cranium,  and  with  those  of  the  integuments. 

Of  the  Sinuses  of  the  Dura  Mater.- — The  sinuses  are  large  cavities 
placed  between  the  two  laminae  of  the  dura  mater,  and  receive  the 
blood  from  the  veins  of  the  pia  mater.  They  are  formed  by  the 
separation  of  these  laminae,  and  are  lined  by  a membrane  corres- 
ponding with  the  internal  coat  of  the  veins. 

1.  The  Sinus  Longitudinalis  Superior  extends  along  the  whole 
base  of  the  falx  cerebri,  from  the  ethmoid  bone  to  the  tentorium, 
where  it  terminates  in  the  lateral  sinuses.  It  begins  at  the  foramen 
coecum  in  a small  pointed  manner,  and,  according  to  some  anato- 
mists, by  a small  vein,  which  passes  from  the  nose  through  this  fora- 
men; it  is  successively  increased  in  size  from  before  backwards,  and 
is  of  a prismatic  shape.  One  side  of  the  prism  is  upwards,  and,  of 
course,  is  formed  by  the  external  lamina  of  the  dura  mater ; while 
the  other  two  parietes  are  lateral,  and  are  formed  by  the  duplicature 
of  the  internal  lamina.  Its  cavity  presents  a number  of  small  cords, 
round  or  flattened,  passing  from  one  side  to  the  other;  they  are  called 
Chordae  Willisii  or  Trabeculae,  and  prevail  principally  at  its  back 
part. 

The  longitudinal  sinus  receives  on  each  side  from  ten  to  twelve 
large  veins,  which  bring  the  blood  from  the  pia  mater.  Those  from 
the  convex  surface  of  the  brain  are  joined  just  before  entering  the 
sinus,  by  such  as  belong  to  the  flat  side  of  the  hemispheres.  These 
veins  enter  the  sinus,  for  the  most  part,  obliquely  forwards,  or  in  a 
manner  opposed  to  its  circulation.  They  are  also  furnished  with 
valves,  which  circumstance,  besides  their  oblique  entrance  into  the 
sinus,  is  a provision  against  their  being  filled  by  the  regurgitating 
blood.  The  most  posterior  ones  previously  glide  eight  or  ten  lines 
between  the  laminse  of  the  dura  mater,  and  are  somewhat  tortuous. 
This  sinus  also  receives  several  veins  from  the  bones,  and  some  from 
the  scalp,  which  traverse  the  bones  at  different  places:  among  the 


MEMBRANES  OF  THE  BRAIN. 


373 


largest  of  them  are  those  that  come  through  the  parietal  foramina. 
The  dura  mater  itself  sends  some  of  its  veins  into  this  sinus. 

Glandules  Pacchioni.  In  the  longitudinal  sinus,  towards  its  posterior 
part,  is  found  a considerable  but  variable  number  of  small  granular 
bodies ; some  in  clusters,  others  insulated  ; and  from  the  size  of  a pin’s 
head  to  a line  or  more  in  diameter.  They  are  the  Glandulse  Pacchioni : 
they  have  no  excretory  ducts  that  have  been  discovered,  and  it  is  en- 
tirely uncertain  whether  any  specific  fluid  is  secreted  from  them.  These 
bodies  are  also  to  be  found  on  the  surface  of  the  dura  mater  near 
this  sinus;  some  of  them,  indeed,  make  foramina  through  the  dura 
mater,  and  corresponding  depressions  in  the  skull.  One  on  each 
side,  larger  than  usual,  and  near  the  parietal  foramen,  is  remarkable 
for  this. 

2.  The  Sinus  Laterales,  one  on  each  side,  are  situated  in  the  base 
of  the  tentorium,  and  follow  its  course  along  the  grooves  of  the  oc- 
cipital and  parietal  bones.  They  then  leave  the  tentorium  and  go 
along  the  groove  in  the  mastoid  portion  of  the  temporal  bones  to 
reach  the  posterior  foramina  lacera,  where  they  terminate  in  the  in- 
ternal jugular  veins.  Their  shape  is  ovoidal,  instead  of  prismatic, 
as  the  longitudinal  sinus  is  ; they  are  also  larger  than  it. 

The  sinus  of  the  right  side  is  very  frequently  larger  than  that  of 
the  left,  and  seems  to  be  more  a continuation  of  the  superior  longi- 
tudinal sinus.  In  some  rare  cases  one  of  these  sinuses  is  deficient. 

The  lateral  and  inferior  veins  of  the  cerebrum,  and  the  inferior 
veins  of  the  cerebellum  run  into  the  lateral  sinuses. 

3.  The  Sinus  Longitudinalis  Inferior  is  situated  in  the  falx  cere- 
bri just  above  its  concave  edge.  It  is  much  smaller  than  the 
superior,  and  terminates  behind  in  the  sinus  quartus.  It  receives 
the  veins  of  the  falx,  and  a few  from  the  corresponding  parts  of 
the  hemispheres. 

4.  The  Sinus  Quartus,  or  Rectus,  is  situated  in  the  tentorium, 
where  the  latter  is  joined  by  the  falx  major  or  cerebri.  It  is  trian- 
gular or  prismatic,  and  runs  from  the  anterior  margin  of  the  tento- 
rium to  the  posterior,  where  it  terminates  in  the  extremity  of  the  lon- 
gitudinal sinus.  The  general  union  which  is  there  formed  between 
the  longitudinal,  the  fourth,  and  the  lateral  sinuses,  constitutes  the 
Torcular  Hierophili. 


374 


NERVOUS  SYSTEM. 


The  anterior  extremity  of  the  fourth  sinus,  besides  receiving  the 
inferior  longitudinal,  is  joined  by  the  Vena  Galeni,  a single  trunk, 
formed  by  the  junction  of  the  two  veins  of  the  middle  of  the  velum 
interposition,  and  extending  from  the  posterior  margin  of  the  fornix 
to  the  beginning  of  the  sinus  quartus.  The  Sinus  Quartus,  in  its 
course,  also  receives  the  superior  veins  of  the  cerebellum,  with  the 
exception  of  the  most  anterior  ones,  which  terminate  in  the  Vena 
Galeni. 

5.  The  Sinus  Petrosi  are  small  cylindrical  cavities,  and  are  so 
called  from  being  situated  on  the  petrous  bone.  There  are  two 
on  each  side ; one  above  and  the  other  below.  The  former  is  the 
Superior,  and  runs  from  the  cavernous  sinus  along  the  superior 
margin  of  the  petrous  bone  to  join  the  lateral  sinus,  where  the  latter 
quits  the  tentorium  to  descend  towards  the  base  of  the  cranium. 
The  other  Petrous  Sinus  is  the  Inferior.  It  is  larger  than  the  su- 
perior, and  arises,  also,  from  the  cavernous  sinus  by  its  posterior 
margin.  It  then  runs  along  the  fissure  between  the  occipital  and 
the  petrous  bone,  leaving  its  mark  on  the  margin  of  these  bones, 
but  principally  oh  the  former,  and  then  terminates  in  the  lateral 
sinus  just  above  the  posterior  foramen  lacerum. 

6.  The  Sinus  Cavernosi,  one  on  each  side,  are  also  formed  by 
a separation  of  the  two  laminae  of  the  dura  mater,  though  their 
shape  is  so  different  from  that  of  the  others.  They  are  situated 
at  the  sides  of  the  sella  turcica,  and  on  the  body  of  the  sphenoid 
bone.  Their  cavity  is  very  irregular,  and  is  furnished  with  a 
number  of  filaments,  which  cross  in  every  direction,  and  give  it  a 
cellular  arrangement.  The  internal  carotid  artery  and  the  sixth 
nerve  traverse  it,  but  are  protected  by  its  lining  membrane  being 
reflected  over  them. 

The  cavernous  sinus  anastomoses  in  front  with  the  circular  sinus, 
and  behind  with  the  two  petrous  sinuses  and  the  anterior  occipital. 
It  receives,  in  front,  the  ophthalmic  veins  ; from  above,  the  ante- 
rior and  inferior  cerebral  veins;  and  on  the  sides,  some  veins  from 
the  dura  mater. 

7.  The  Sinus  Circularis  is  placed  in  the  sella  turcica,  and  sur- 
rounds the  pituitary  gland.  It  is  a small  cavity  which  receives  the 


MEMBRANES  OF  THE  BRAIN. 


375 


veins  of  this  gland,  and,  as  just  mentioned,  communicates  with 
the  cavernous  sinus. 

8.  In  the  posterior  part  of  the  base  of  the  cranium,  there  are  also 
some  other  sinuses,  called,  from  their  position,  Occipital.  One  of 
these,  the  Anterior,  is  upon  the  basilar  process  of  the  os  occipitis, 
and  extends  itself  directly  across  the  bone,  from  the  hind  part  of 
one  cavernous  sinus  to  the  corresponding  point  of  the  other ; and  is, 
therefore,  a means  of  communication  between  these  two  cavities. 
Another  of  these  sinuses,  the  posterior,  extends  from  the  region  of 
the  TorcularHierophili,  or  the  upper  extremity  of  the  lateral  sinuses, 
along  the  base  of  the  falx  cerebelli,  to  the  posterior  margin  of  the 
occipital  foramen,  where  it  bifurcates,  and  then  goes  along  the 
margin  of  this  foramen  to  discharge  itself  into  each  lateral  sinus  at 
the  posterior  foramen  lacerum. 

The  smaller  sinuses  about  the  base  of  the  cranium,  besides  the 
outlets  mentioned,  have  collateral  ones,  which  pass  at  different 
places  through  the  base  of  the  cranium,  and  run  into  the  branches 
of  the  internal  jugular  vein.  These  communications,  as  mentioned 
in  the  account  of  the  veins,  were  known  to  Santorini,  and  are 
called  his  Emissaries. 


Of  the  Tunica  Arachnoidea. 

This  membrane  is  the  second  of  the  envelopes  of  the  brain,  and 
is  spread  over  the  surface  of  the  pia  mater,  adhering  to  it  closely  in 
the  greater  part  of  its  extent.  It  is  so  diaphanous  and  thin,  as  its 
name  implies,  that  it  is  distinguished  with  some  difficulty,  wherever 
it  adheres  to  the  pia  mater ; which  it  does  all  over,  wdth  the  excep- 
tion of  a few  places  on  the  basis  of  the  brain,  as,  for  example, 
just  in  front  of  the  tuber  annulare,  and  behind  the  medulla  oblon- 
gata. There  this  membrane  may  be  seen  stretched  from  one  pro- 
minence to  another,  and  separated  considerably  from  the  pia  mater. 
It  does  not  dip  into  the  fissures  of  the  brain,  but  goes  directly  across 
them,  from  the  ridge  of  one  convolution  to  that  of  the  adjacent,  so 
that  it  is  entirely  smooth  and  uniform  in  its  distribution.  Notwith- 
standing the  general  closeness  of  its  connexion  with  the  pia  mater, 
it  may  yet  be  separated  from  it  by  careful  dissection,  by  slight 


376 


NERVOUS  SYSTEM. 


maceration,  or  by  the  use  of  the  blow-pipe  ; dropsical  effusions  fre- 
quently make  out  the  distinction  between  the  two  membranes ; also 
the  deposite  of  coagulating  lymph. 

Considering  this  membrane  as  a single  layer,  we  have  to  speak 
of  the  dura  mater,  as  lying  loosely  upon  it.  But  the  authority  of 
Bichat  sanctioned  by  the  testimony  of  many  other  anatomists,  has 
assigned  to  it  a much  more  considerable  extent.  For  it  seems  to 
be  well  ascertained,  both  by  analogy  and  by  observation,  that  it  is 
a sac  ; which  besides  covering  the  external  surface  of  the  pia  mater, 
is  reflected  over  the  internal  surface  of  the  dura  mater,  and  gives 
to  the  latter  its  smooth  shining  appearance.*  This  lining  is  on  the 
same  principle  that  the  serous  lamina  of  the  pericardium  lines  its 
fibrous  lamina,  or  that  the  synovial  membrane  lines  the  ligamentous 
attachments  of  an  articulation.  In  the  early  periods  of  life,  it  may 
be  separated  from  the  dura  mater,  by  dissection.  Yicq.  D’Azyr 
has  related  a case  in  which  it  was  detached  by  a collection  of  pus. 
Its  places  of  reflection  to  the  dura  mater  are  on  the  basis  of  the  cra- 
nium, where  the  blood  vessels  and  nerves  pass  into  the  sheaths 
formed  by  the  dura  mater,  and  along  the  blood  vessels  entering  into 
the  sinuses.  This  membrane  is  continuous  with  the  tunica  arach- 
noidea  of  the  medulla  spinalis. 

The  tunica  arachnoidea  is  considered  to  pass  into  the  ventricles 
of  the  brain  by  the  same  apertures  that  the  pia  mater  does,  but  it  is 
much  less  manifest  there  than  elsewhere. f 

The  texture  of  this  membrane  is  exceedingly  delicate  and  fine. 
It  is  always  found,  in  health,  in  a transparent  state,  and  is  not  fur- 
nished with  red  blood  vessels,  but  nerves  are  considered  by  Pur- 
kinje  to  exist  in  it.  It  secretes  a sort  of  halitus,  or  synovia,  which 
facilitates  the  motions  of  the  brain,  and  prevents  it  from  adhering. 
Occasionally,  this  secretion  is  so  much  augmented  as  to  constitute  a 
genuine  dropsy. 

* There  are  some  excellent  and  unequivocal  examples  of  this  in  the  Wistar  Mu- 
seum, prepared  by  the  Author. 

•j-  As  the  ventricles  of  the  encephalon  are  but  fissures  in  its  structure,  this  ar- 
rangement is  in  opposition  1o  that  of  the  fissures  on  the  surface  of  the  encephalon, 
and  in  fact  may  be  doubted  from  its  defective  evidence,  excepting  in  the  case  of  the 
Velum  interpositum. 


MEMBRANES  OF  THE  BRAIN, 


377 


Of  the  Pia  Mater. 

The  Pia  Mater,  or  Tunica  Cerebri  Vasculosa,  is  in  contact  with 
the  substance  of  the  brain.  It  also  is  extremely  delicate,  but,  un- 
like the  last,  is  furnished  with  an  immense  number  of  blood  vessels 
which  go  to  or  return  from  the  brain,  and  are,  in  most  subjects,  so 
abundant  that  they  give  a florid  appearance,  at  a little  distance, 
to  the  wkole  membrane.  Its  external  face  appears  entirely  smooth, 
owing  to  its  being  covered,  and  its  processes  cemented  together  by 
the  tunica  arachnoidea  ; but  its  internal  face  exhibits  these  pro- 
cesses as  penetrating  to  the  bottom  of  the  fissures  of  the  brain  ; con- 
sequently, it  is  very  unequal. 

The  pia  mater  presents,  along  the  course  of  the  longitudinal  sinus, 
an  abundance  of  those  small  graniform  bodies,  existing  also  in  this 
sinus,  and  called  Glandulse  Pacchioni.  They  beset  the  veins  as  they 
enter  into  the  longitudinal  sinus,  and  even  follow  them  there,  so  that 
there  is  a chain  of  them  from  the  surface  of  the  pia  mater,  into  the 
sinus.  They  are  frequently  so  abundant  on  the  superior  part  of  the 
hemispheres,  near  the  great  fissure,  that  they  cause  the  dura  and  pia 
mater  to  adhere,  as  if  from  inflammation.  It  is  the  larger  of  this 
kind  which  frequently  produce  an  absorption  of  the  dura  mater,  and 
of  the  internal  table  of  the  skull.  These  bodies  are  also  found,  along 
with  the  pia  mater,  in  the  ventricles  of  the  brain,  as  at  the  external 
margin  of  the  plexus  choroides,  around  the  pineal  gland,  and  at  the 
bottom  of  the  fourth  ventricle. 

The  Glandulse  Pacchioni,  wherever  found,  present  a similar  ap- 
pearance and  structure,  but  varying  much  in  size:  they  are  generally 
in  clusters,  which  repose  on  common  bases.  Anatomists  differ  much 
in  their  opinion  concerning  them.  Bichat  acknowledges  his  com- 
plete ignorance  on  the  subject;  Portal  says  that  they  are  only  con- 
geries of  vessels  or  of  cellular  bodies  filled  with  fat.  Meckel  states, 
that  as  they  are  found  especially  in  the  later  periods  of  life,  and 
never  before  birth,  and  as  they  never  exist  in  very  great  abundance, 
except  in  persons  who  have  often  experienced  diseases  of  the  head, 
and  are  not  observed  in  any  animal ; so  we  are  forced  to  consider 
them  as  morbific  productions,  and  not,  as  Pacchioni  conceived, 
glands  whose  excretory  ducts  opened  into  the  ventricles  of  the  brain 
and  into  the  sinuses  of  the  dura  mater. 

Vol.  II.— 33 


378 


NERVOUS  SYSTEM. 


The  Pia  Mater  covers  the  upper  surface  of  the  cerebrum  with  such 
uniformity  as  not  to  require  a detailed  description  of  it ; where  it  sinks 
into  the  great  fissure  between  the  hemispheres,  it  adheres  from  the 
two  sides  just  above  the  corpus  callosum.  On  the  basis  of  the  brain, 
it  penetrates  deeply  into  the  anterior  fissure,  or  the  Fissura  Sylvii ; 
is  reflected  over  the  inequalities  of  the  brain,  but  never  in  such  a 
way  as  to  leave  them;  and  secures  the  bottom  of  the  third  and  of  the 
fourth  ventricle. 

The  distribution  of  the  pia  mater,  over  the  ventricles  of  the  brain, 
is  more  complicated  than  that  over  its  periphery,  and  it  may  be  re- 
marked, that  this  portion  is  called,  by  some  anatomists,  the  Internal 
Pia  Mater ; that  its  texture  is  much  more  delicate,  and  net -like,  and 
that  it  adheres  more  closely  to  the  subjacent  parts.  Being  extended 
from  the  superior  surface  of  the  Cerebellum  and  of  the  Pons  Varolii, 
it  enters  into  the  third  ventricle,  under  the  posterior  margin  of  the 
fornix,  by  the  large  transverse  fissure  between  the  latter  and  the 
tubercula  quadrigemina.  By  its  course  between  the  fornix  and  tha- 
larni,  it  constitutes  the  Velum  Interpositum,  or  the  Tela  Choroidea 
ofVicq.  D’Azyr.  The  pia  mater  is  also  introduced  into  the  inferior 
cornu  of  the  lateral  ventricles  along  the  internal  margin  of  the  hippo- 
campus major,  at  the  side  of  the  pons  varolii;  and  into  the  fourth 
ventricle  from  its  bottom  part. 

The  several  plexuses  of  vessels  found  in  the  ventricles  of  the  brain 
have  for  their  basis  the  pia  mater;  which  is  there  arranged  into  a 
great  number  of  folds,  some  of  them  being  longitudinal  and  others 
crossed.  Their  formation,  according  to  the  new  views  which  have 
been  taken  of  the  development  and  growth  of  the  brain,  by  Tiede- 
mann,  depends  upon  the  internal  membrane  of  the  brain  contracting 
itself  as  it  finishes  the  deposite  of  medullary  matter  called  Centrum 
Ovale.  The  vessels  of  the  plexuses  are  the  arteries,  which  are  spent 
upon  the  surface  of  the  ventricles,  and  the  veins  derived  from  the 
same ; the  latter  are  much  more  numerous  than  the  first. 

Of  the  Structure  of  the  Pia  Mater. — The  pia  mater  is  commonly 
spoken  of  as  a complete  membrane,  yet  its  structure  is  different  from 
that  of  membranes  generally,  inasmuch  as  it  is  a net-work,  the  meshes 
of  which  are  formed  by  arteries  and  veins,  and  the  interstices  filled 
up  by  a loose,  weak  cellular  substance.  Bichat  has  very  justly  ob- 
served, that  the  union  with  the  tunica  arachnoidea  is  solely  on  the 


THE  MEDULLA  OBLONGATA. 


379 


part  of  this  cellular  substance ; whereas,  the  union  with  the  cerebrum 
is  confined  to  the  vessels,  which  are  extremely  numerous  and  very 
small  before  they  penetrate  it,  and  appear  as  bloody  points  when  we 
cut  into  the  substance  of  the  brain.  The  principal  arterial  trunks  of 
the  pia  mater,  being  the  internal  carotids  and  the  vertebrals  and  their 
branches,  are  at  the  basis  of  the  brain;  these  trunks  divide  into 
smaller  branches,  on  the  convolutions  and  in  the  fissures.  The 
primary  divisions  again  divide  and  subdivide  into  tubes  not  much 
exceeding  the  size  of  the  capillary  vessels.  In  this  last  state  they 
enter  the  brain  and  may  be  seen  very  readily,  either  by  a fine  in- 
jection, or  by  tearing  up  the  pia  mater.  Purkinje  is  said  to  have 
traced  nerves  into  it.* 


SECT.  II. — OF  THE  MEDULLA  OBLONGATA. f 

According  to  the  usage  of  the  best  authorities  of  the  present  day, 
who  follow  in  the  description  of  the  central  parts  of  the  nervous  sys- 
tem, the  order  of  their  development  in  the  human  subject,  and  also 
of  their  appearance  in  animals,  I shall  describe  the  encephalon  from 
below  upwards  instead  of  from  above  downwards.  The  preference 
thus  shown  is,  perhaps,  principally  serviceable  in  fixing  upon  the 
mind  the  order  of  growth  and  appearance,  which,  according  to 
well  established  experiments,  are  exactly  in  the  order  of  importance 
to  life. 

The  Medulla  Oblongata,  also  called  Bulbus  Rachidicus,  ex- 
tends from  the  superior  margin  of  the  first  cervical  vertebra  to  the 
middle  of  the  basilar  process  of  the  os  occipitis.  It  becomes  gra- 
dually larger  as  it  ascends,  and  is  about  an  inch  in  length,  and  eight 
lines  wide  at  its  base.  It  is  by  no  means  so  cylindroid  as  the  me- 
dulla spinalis,  but  presents  several  risings  and  depressions  on  its 
surface. 

The  under  surface  of  the  Medulla  Oblongata  is  divided  longi- 
tudinally by  the  middle  fissure,  a continuation  of  that  on  the  front  of 
the  Medulla  Spinalis.  The  fissure  is  two  or  three  lines  deep,  which 
is  rendered  manifest  by  removing  the  pia  mater.  The  Corpora  Py- 
ramidalia  are  placed  one  on  either  side  of  it,  and  are  oblong  bodies ; 


* See  Serous  Membranes. 


t Anat.  Atlas.  Figs.  524,  528,  529,  530. 


3S0 


NERVOUS  SYSTEM. 


being  a continuation  of  the  cords  that  decussate  from  the  opposite 
sides  of  the  spinal  marrow.  These  bodies  occupy  the  whole  length 
of  the  Medulla  Oblongata,  increase  in  breadth  as  well  as  in  eleva- 
tion during  their  ascent,  and  are,  lastly,  somewhat  constricted  or 
diminished  abruptly,  where  they  join  the  Protuberantia  Annularis  or 
Cerebralis.  Precisely  at  the  latter  point,  between  their  bases,  is  a 
deep  triangular  pit,  into  which  penetrates  the  pia  mater.  J.  F. 
Meckel  says  that  they  are  united  at  their  lower  extremities  by  a 
small  transverse  medullary  Commissure  of  a line  and  a half  in 
breadth.  This  junction  is  above  the  decussation  of  the  cords  from 
which  the  corpora  Pyramidalia  arise. 

The  Eminentise  Olivares  are  two  bodies ; one  on  either  side,  at 
the  external  margin  of  the  corpus  pyramidale.  They  are  about 
seven  lines  long:  two  and  a half  wide,  and  are  elevated  to  the 
height  of  one  line.  The  elevation  ceases  somewhat  short  of  the  an- 
nular protuberance,  but  their  interior  structure  is  continued  into  the 
latter,  and  may  be  traced  into  the  thalamus  nervi  optici. 

Like  the  pyramidalia,  those  bodies  are  medullary  externally ; but 
within,  there  is  a nucleus  of  cineritious  matter,  called.,  from  the  irre- 
gularities of  its  margin,  Corpus  Fimbriatum,  and  wrhich  encloses 
some  medullary  matter.  The  corpus  fimbriatum  is  open  at  the  inner 
circumference,  and  has  the  medullary  matter  which  it  contains,  conti- 
nuous there  with  the  substance  of  the  corpus  pyramidale.  Below,  its 
circumference  is  continuous  with  the  cineritious  matter  of  the  me- 
dulla spinalis.  In  the  slight  depression  between  the  corpus  pyra- 
midale and  the  eminentia  olivaris,  are  the  roots  of  the  hypoglossal 
nerve. 

The  Corpora  Restiformia,  also  one  on  either  side,  are  placed  at 
the  lateral  posterior  margins  of  the  medulla  oblongata,  just  posterior 
to  the  eminentise  olivares ; and  are  readily  brought  into  view  by  ele- 
vating the  contiguous  parts  of  the  cerebellum.  They  are  oblong 
risings  of  an  inch  in  length  ; their  lower  extremities  are  in  contact, 
and  project  where  they  begin  to  arise  from  the  borders  of  the  pos- 
terior fissure  of  the  medulla  oblongata  ; they  then  diverge,  and 
extend  forwards  and  upwards  to  terminate  above  in  the  cere- 
bellum. 

The  corpus  restiforme  is  formed  of  medullary  matter,  and  is  a 
continuation  of  the  posterior  cord  of  the  medulla  spinalis.  From 


THE  MEDULLA  OBLONGATA. 


* 


381 


its  superior  posterior  margin  a thin  medullary  lamina  of  about  three 
lines  square  arises,  and  being  sustained  by  the  pia  mater,  advances 
to  meet  its  fellow,  but  does  not  absolutely  touch  it.*  From  the  an- 
terior margin  of  each  corpus  restiforme  there  departs  a second  pro- 
cess of  medullary  matter,  larger  and  more  thick  than  the  preceding, 
and  being  covered  by  the  roots  of  the  pneumogastric  and  glosso- 
pharyngeal nerves,  adheres  to  the  plexus  Choroides  of  the  fourth 
ventricle. 

The  superior  face  of  the  medulla  oblongata  is  excavated  between 
the  corpora  restiformia,  in  such  a way  as  to  present  the  outline  of 
a writing  pen,  and  is  therefore,  called  Calamus  Scriptorius ; which 
forms  a considerable  part  of  the  floor  of  the  fourth  ventricle  of  the 
Brain,  or  the  sinus  rhomboideus.  The  fissure,  in  its  middle,  cor- 
responds with  the  slit  of  a pen,  the  nib  being  downwards ; and  the 
fissure  extends  from  the  posterior  fissure  of  the  medulla  spinalis  the 
whole  length  of  the  medulla  oblongata. 

The  calamus  scriptorius  is  marked  by  several  streaks  of  medullary 
matter,  which  extend  themselves  transversely  with  a very  slight  de- 
gree of  obliquity  upwards,  and  reach  the  external  margin  of  the 
corpus  restiforme  of  the  corresponding  side.  These  medullary  striee 
present  some  varieties  in  regard  to  their  volume,  number,  and  ar- 
rangement. Sometimes  they  are  slightly  elevated  narrow  lines, 
which  are  perfectly  distinct  from  each  other,  and  from  one  to  four- 
teen in  number.  On  other  occasions  their  volume  is  greater,  but 
they  are  not  so  numerous.  They  generally  extend,  either  one  or  all, 
from  the  middle  fissure  to  the  commencement  of  the  auditory  nerve, 
and  are  thereby  a part  of  its  origin.  Sometimes  the  anterior  ones 
are  directed  towards  the  origin  of  the  trigeminus  nerve,  but  their 
union  with  it  is  not  yet  ascertained  ; the  posterior  ones  are  sometimes 
blended  with  the  radical  filaments  of  the  pneumogastric  nerve.  The 
strise  themselves,  are  sometimes  interwoven  or  blended,  and  pass 
the  boundary  of  the  middle  fissure  to  join  with  those  of  the  other 
side.  Their  roots  may  be  traced  along  the  middle  fissure,  to  the 
front  or  under  surface  of  the  medulla  oblongata.  If  a medulla  ob- 
longata be  well  hardened  in  spirits  of  wine  and  then  torn  open  through 
its  middle  fissures,  the  surface  thus  exposed  presents  itself  as  formed 
almost  entirely  of  the  filaments  just  mentioned,  running  from  back 
to  front.  In  some  cases  I have  seen  them  at  their  anterior  ends  pass 

* Called  Pons  Sinus  Rhomboidei  by  J.  F,  Meckel. 

33* 


382 


NERVOUS  SYSTEM. 


on  so  as  to  form  a superficial  layer  encircling  the  front  of  the  medulla 
oblongata  like  threads  wound  around  a bunch  of  rods.  Meckel, 
whose  observations  on  this  subject  are  highly  interesting,  is  disposed 
to  consider  the  striae  not  only  as  forming  the  roots  of  the  auditory 
nerve,  but  as  also  related  closely  to  the  trigeminus  and  to  the  pneu- 
mogastric. 

On  the  surface,  also,  of  the  fourth  ventricle,  or  sinus  rhomboi- 
deus,  but  in  advance  of  the  preceding  striae,  there  is  another,  on 
each  side,  still  larger,  which  may  be  distinguished  by  its  always  be- 
ginning at  some  distance  from  the  middle  fissure.  Its  direction  is 
transverse,  and  it  passes  just  above  the  anterior  extremity  of  the 
corpus  restiforme,  to  run  into,  or  to  assist  in  forming,  the  root  of  the 
auditory  nerve.  Its  existence  is  much  more  constant  than  that  of 
the  others.  It  is  considered  as  an  assistant  ganglion  to  the  auditory 
nerve,  and  in  cases  of  deafness  has  been  deficient.  Being  principally 
cineritious,  it  is  called  Fasciola  Cinerea. 

In  tracing  the  continuation  of  the  structure  of  the  medulla  spinalis, 
into  that  of  the  medulla  oblongata,  we  find  that  each  of  the  anterior 
cords  of  the  medulla  spinalis,  besides  crosssing  with  some  of  its 
fasciculi  at  the  place  mentioned,  to  wit,  at  the  decussation  of  Misti- 
chelli,  and  continuing  their  course  upwards  to  form  the  corpus  pyra- 
midale,  sends  off  a larger  fasciculus,  which  ascends  behind  the  emi- 
nentia  olivaris,  and  forms  the  floor  of  the  fourth  ventricle  or  sinus 
rhomboideus.  There  is  yet  another  fasciculus  of  white  matter,  ac- 
cording to  Rosenthal,  between  the  others,  into  which  the  anterior 
column  of  the  medulla  spinalis  is  divided.  He  says,  that  it  touches 
the  eminentia  olivaris,  surrounds  it,  and,  after  having  traversed  the  an- 
nular protuberance,  terminates  in  the  tubercula  quadrigemina. 

The  posterior  cords  of  -the  Spinal  marrow,  being  continued  into 
the  corpora  restiformia,  become  still  more  evidently  divided  into 
two  fasciculi,  from  an  increase  of  their  volume,  than  they  were  in  the 
vertebral  canal.  The  internal  of  these  fasciculi  stops,  by  a pointed 
termination,  near  the  borders  of  the  sinus  rhomboideus,  or  fourth  ven- 
tricle of  the  Brain ; while  the  external  is  continued  on  through  the 
annular  protuberance  to  the  cerebellum. 


PROTUBERANTIA  ANNULARIS. 


383 


SECT.  III. — PROTUBERANTIA  ANNULARIS.* 

The  Annular  Protuberance  ( Protuberantia  Annularis , Nodus 
Cerebri , Pons  Varolii)  is  the  large  projecting  body,  placed  near  the 
centre  of  the  base  of  the  encephalon,  at  the  top  of  the  medulla  ob- 
longata, and  upon  the  junction  of  the  body  of  the  sphenoid  bone 
with  the  basilar  process  of  the  os  occipitis.  It  is  convex,  and  about 
an  inch  in  diameter,  its  transverse  measurement  being  a line  or  two 
larger  than  the  other.  It  is  divided  by  a superficial  fossa  into  two 
symmetrical  halves,  right  and  left. 

When  the  pia  mater  is  removed  from  the  Protuberantia  Annu- 
laris, the  under  surface  of  the  latter  is  seen  to  be  formed  by  trans- 
verse medullary  fibres  which  come  from  the  crura  cerebelli.  When 
these,  which  are  commonly  one  or  two  lines  in  depth,  are  removed 
by  scraping  or  cutting,  a cineritious  matter  is  exposed,  which  is  tra- 
versed by  numerous  layers  of  medullary  matter,  also  going  in  a 
transverse  direction.  About  two  lines  deep  from  the  surface  of  the 
protuberance,  near  the  middle  of  each  of  its  halves,  are  found  some 
longitudinal  medullary  fibres  connected  with  cineritious  matter,  and 
wdiich  may  be  fairly  traced  as  a continuation  of  the  filamentous 
structure  of  the  pyramidal  bodies.  These  fasciculi,  or  filaments, 
passing  on  through  the  protuberance,  are  continued  so  as  to  form 
the  under  surface  of  the  crura  of  the  cerebrum. 

Lying  still  deeper  than  the  medullary  fibres  alluded  to,  there  is 
an  accumulation  of  cineritious  matter,  intermixed  with  perpendicular 
medullary  layers  situated  one  behind  the  other.  Behind  (or  above 
when  we  stand  erect)  this  intertexture,  a small  fasciculus  (the  cord 
described  by  Rosenthal)  of  medullary  matter  exists,  which  is  a con- 
tinuation of  the  intermediate  fasciculus  of  the  anterior  medullary 
cord  of  the  medulla  spinalis,  and  may  be  traced  afterwards  to  the 
superior  face  of  the  crus  cerebri,  where  it  terminates  as  alleged  by 
Rosenthal,  in  the  Tubercula  Quadrigemina. 

At  the  centre  of  the  posterior  margin  of  the  Pons,  we  find  some- 
times an  elongated  triangular  process,  which  penetrates  deeply  be- 
tween the  bases  of  the  Pyramids,  and  may  be  traced  to  the  posterior 
middle  fissure  of  the  Medulla  Oblongata. 


* Amt.  Atlas,, Figs-  524-531. 


3S4 


NERVOUS  SYSTEM. 


SECT.  IV. — OF  THE  CEREBELLUM.* 

The  Cerebellum,  being  placed  in  the  posterior  fossa?  of  the  era- 
nium  is  separated  by  the  tentorium  from  the  posterior  lobes  of  the 
cerebrum,  beneath  which  it  lies.  It  is  connected  with  the  Pons 
Varolii  by  a trunk  of  medullary  matter  on  each  side,  called  the  Crus 
of  the  Cerebellum ; and  which  is  a root  of  the  medullary  matter 
entering  into  the  composition  of  the  pons. 

It  is  of  a rounded  form,  and  wrell  fitted  to  the  cavity  in  which  it 
reposes.  It  is  convex  above  and  below;  measures  about  four 
inches  in  its  transverse  diameter,  two  and  a half  in  thickness,  and 
about  the  same  from  before  backwards.  The  upper  face  is  divided 
into  two  equal  parts  or  halves,  by  a middle  ridge,  while  the  lower 
face  is  divided  in  the  same  way  by  a fossa.  These  halves  are  called 
hemispheres  ; their  surface  is  marked  by  many  horizontal  and  trans- 
verse  fissures,  the  edges  of  w’hich  are  kept  closed  by  the  adhesion  of 
the  pia  mater. 

The  fissures  are  interposed  between  the  laminae  or  convolutions 
of  the  cerebellum,  which  for  the  most  part  converge  towards  its 
medullary  trunk ; the  larger  fissures  are  behind,  while  the  shortest 
are  in  front  near  the  annular  protuberance.  The  pia  mater  pene- 
trates to  the  bottom  of  these  fissures,  some  of  which,  when  exposed 
fully  by  its  removal,  are  found  to  extend  to  the  depth  of  an  inch  or 
more.  One  of  these  fissures  which  exists  on  the  superior  surface  of 
the  cerebellum,  half  an  inch  distant  from  the'  posterior  and  external 
margin  of  the  latter,  has  a circular  course,  and  is  so  well-marked  by 
its  size  and  depth  that  it  is  called  the  Sulcus  Superior  Cerebelli. 
Another,  situated  under  similar  circumstances  on  the  inferior  surface 
of  the  cerebellum,  is  called  the  Sulcus  Inferior  Cerebelli.  On  the 
latter  surface,  also,  there  are  two  or  three  more  of  a middle  size, 
situated  between  the  sulcus  inferior  and  the  annular  protuberance. 
These  larger  sulci  have  given  occasion  to  anatomists  to  multiply 
most  unreasonably  the  number  of  lobes  of  which  the  cerebellum 
consists.  Bichat’s  mode  of  description  is  preferable  : he  says,  that 
by  cutting  (vertically)  through  one  of  the  hemispheres  of  the  cere- 
bellum, so  as  to  expose  the  thickest  part  of  its  medullary  matter,  six 
or  seven  principal  fissures  will  be  seen,  which,  by  penetrating  to  a. 


* Auat.  Atlas,  Figs.  525  to  531,  inclusive 


THE  CEREBELLUM. 


385 


considerable  depth,  divide  the  cineritious  portion  into  as  many  con- 
verging parts.  In  the  interior  of  these  fissures  there  are  much 
smaller  ones,  which  pass  at  right  angles  to  them.  On  the  surface 
or  periphery  of  the  cerebellum,  in  the  intervals  of  the  larger  fissures, 
there  are  many  small  ones,  which,  though  nearly  horizontal,  termi- 
nate in  each  other  by  acute  angles. 

The  superior  middle  ridge  of  the  cerebellum,  from  its  shape  and 
position,  is  called,  by  Vicq.  D’Azyr,  Vermis  Superior ; the  anterior 
extremity  of  which,  from  its  elevation,  is  the  Monticulus  Cerebelli. 

The  middle  inferior  part  of  the  cerebellum,  which  presents  the 
deep  sulcus  running  longitudinally  and  forming  the  division  into 
hemispheres,  has  a long  ridge  occupying  the  sulcus.  This  ridge 
is  the  Vermis  Inferior  of  Vicq.  D’Azyr  and  is  so  concealed  by  the 
adjacent  portions  of  the  hemispheres,  that  a good  view  of  it  can  be 
got  only  by  removing  the  arachnoidea,  the  pia  mater  and  pushing  the 
hemispheres  aside.  The  transverse  fissures  which  penetrate  it,  and 
its  general  irregularity  of  surface,  will  then  be  sufficiently  distinct. 
The  pia  mater  and  arachnoidea  pass  from  the  fore  part  of  this  body 
to  the  medulla  oblongata,  and  thus  assist  in  forming  the  floor  of  the 
fourth  ventricle  ; which,  without  this  reflection  would  be  exposed. 
The  central  part  of  the  cerebellum  as  formed  by  the  vermis  superior 
and  by  the  vermis  inferior,  is  the  Fundamental  Portion  of  Gall  and 
Spurzheim. 

At  the  root  of  the  crus  cerebelli  are  two  small  protuberances;  the 
one  below  it,  in  the  erect  position,  is  the  Lobulus  Amygdaloides, 
and  the  other  the  Lobulus  Nervi  Pneumogastrici. 

The  substance  of  the  cerebellum,  is  formed  of  cineritious  matter 
externally,  and  of  medullary  matter  internally.  When  a vertical 
section  of  it  is  made  through  the  middle  of  one  of  its  hemispheres, 
the  medullary  neurine  or  matter  puts  on  the  appearance  of  the  thuya 
or  arbor  vitae,  the  roots  and  ramifications  of  whose  limbs,  even  to 
their  smallest  extremities,  are  surrounded  by  cineritious  neurine  or 
matter.  In  this  view,  there  appears  to  be  more  cineritious  than 
white  matter ; but  when  a horizontal  cut  is  made  from  the  periphery 
to  the  centre,  parallel  with  one  of  the  deep  concentric  fissures,  the 
proportion  of  medullary  matter  seems  to  be  much  more  considerable ; 
and  the  arbor  vitas  arrangement  is  proved  to  depend  upon  the  laminae 
of  medullary  matter  radiating  from  the  centre,  or,  in  other  words, 
from  the  massive  medullary  trunk  in  the  interior  of  the  hemisphere 
of  the  cerebellum.  Each  of  these  radiations  commences  by  a root 


3S6 


NERVOUS  SYSTEM. 


of  considerable  size,  which  divides  and  subdivides  into  branches. 
Each  primitive  radiation,  as  well  as  its  branches,  is  covered  by  its 
own  layer  of  cineritious  matter  about  one  line  in  thickness,  and  is 
kept  perfectly  distinct  from  the  contiguous  ones  by  the  fissures  which 
extend  internally  from  the  periphery  of  the  cerebellum. 

In  the  middle  of  the  trunk  of  the  arbor  vitae,  exists  the  Corpus 
Rhomboideum,  or  Dentatum.  It  is  an  oblong  rounded  body,  jagged 
and  cineritious  in  its  circumference,  but  medullary  within.  Its  con- 
figuration resembles  that  of  the  corresponding  body  in  the  eminentia 
olivaris,  with  the  addition  of  its  being  larger,  and  having  its  outline 
better  marked.  It  is  the  ganglion  of  the  cerebellum  of  Gall  and 
Spurzheim. 

The  Valve  of  Vieussens  ( Velum  Medullare,  Valvula  Cerebelli  or 
Cerebri)  arises  from  the  cerebellum,  just  under  the  anterior  part  of  the 
base  of  the  monticulus,  and  runs  obliquely  upwards  to  terminate  in  the 
testes.  Sometimes  is  it  marked  in  its  middle,  by  a longitudinal  line  or 
slight  fissure,  from  either  side  of  which  proceed  small  lateral  ones.  It  is 
principally  medullary,  and  has  a small  quantity  of  cineritious  matter 
at  its  extremities.  It  is  thinner  in  the  middle  than  at  either  of  its 
margins. 

The  Central  or  Fundamental  Portion  of  the  Cerebellum  exhibits 
also  very  clearly  the  arborescent  arrangement,  and  is  furnished  with 
about  seven  primitive  radiations,  coming  from  a medullary  trunk. 
The  proportion  of  medullary  matter  to  cortical,  is  less  in  it  than  in 
the  hemispheres  of  the  cerebellum.  Each  of  the  primitive  radiations 
may  be  traced  to  some  particular  point  or  prominence  on  the  surface 
of  the  fundamental  portion,  thus  forming  its  basis ; but  this  study  is 
more  curious  than  useful,  though  several  anastomists  have  pur- 
sued it. 

Three  medullary  fasciculi,  on  each  sides  have  now  been  assigned 
to  the  cerebellum ; one  of  these  is  the  continuation  of  the  corpus 
restiforme  of  the  medulla  oblongata ; a second  is  the  valvula  cerebelli ; 
and  the  third,  the  Crus  Cerebelli,  which  joins  the  annular  protuber- 
ance. The  first  two  fasciculi  belong  to  the  middle  or  fundamental 
portion  of  the  cerebellum ; they  are  consequently,  situated  more  in- 
ternally, and  are  partially  concealed  by  the  crus  cerebelli,  and  have 
interposed  between  them  and  the  latter,  the  Corpus  Rhomboideum 
or  Dentatum. 


THE  CEREBRUM. 


387 


SECT.  V. — OF  THE  CEREBRUM.* 

The  Cerebrum  weighs  about  three  pounds,  and  is  seven  times  as 
heavy  as  the  cerebellum.  It  is  ovoidal,  and  measures  about  six 
inches  in  its  antero-posterior  diameter,  five  inches  in  its  greatest 
breadth,  which  is  behind,  and  four  or  five  in  depth.  It  is  separated 
above  by  a deep  fissure,  ( Fissura  Longitudinalis,)  into  two  equal 
parts,  called  Hemispheres.  At  the  bottom  of  this  fissure  by  sepa- 
rating the  contiguous  surfaces  of  it,  is  to  be  seen  a broad  lamina  of 
medullary  matter  passing  from  side  to  side,  and  called  the  Corpus 
Callosum,  which  connects  the  two  hemispheres  together.  The  under 
surface  of  each  hemisphere  is  subdivided  into  three  lobes ; Anterior, 
Middle,  and  Posterior. 

The  anterior  lobes  are  placed  upon  the  anterior  fossae  of  the  base 
of  the  cranium  ; the  Middle,  upon  the  middle  fossae  of  the  same  ; and 
tire  Posterior  Lobes  rest  upon  the  tentorium.  The  two  anterior  lobes 
are  completely  separated  by  the  Fissura  Longitudinalis,  which  ex- 
tends between  them  to  the  base  of  the  cranium ; the  same  is  the  case 
with  the  posterior  lobes  ; the  middle  lobes  have  interposed  between 
them  the  annular  protuberance  and  the  crura  cerebri.  When  the 
pia  mater  is  removed,  the  anterior  lobe  is  seen  to  be  marked  off  from 
the  middle  lobe  by  a deep  sulcus,  the  fissure  of  Sylvius,  in  the  under 
surface  of  the  cerebrum,  corresponding,  in  its  position,  with  the  pos- 
terior margin  of  the  Lesser  Sphenoidal  Wing.  The  boundary  be- 
tween the  middle  and  the  posterior  lobe  is,  by  no  means,  well  de- 
fined on  the  basis  of  the  brain,  but  it  is  agreed  to  consider  as  pos- 
terior lobe,  all  that  part  of  the  hemisphere  which  rests  upon  the  ten- 
torium. 

The  periphery  of  the  cerebrum  is  formed  into  convolutions,!  ( Gyri ) 
which  give  it  an  unequal  tortuous  surface,  resembling  the  intestines 
of  a small  child.  These  convolutions  are  separated  by  fissures  (Sulci) 
of  depths  varying  from  an  inch  to  two  inches  or  more.  The  con- 
volutions proceed  in  diversified  and  complicated  courses,  which 
never  correspond  in  different  individuals,  and  seldom  exactly  on  the 
two  hemispheres  of  the  same  brain.  Though  their  summit  is  gene- 
rally convex,  yet  some  of  them  have  it  depressed  slightly,  which  is 

* Anat.  Atlas,  Figs.  543  to  547,  inclusive, 
t Anat.  Atlas  Fig.  532,  &c. 


388 


NERVOUS  SYSTEM. 


considered  a proof  of  each  convolution  being  divisible  into  two 
halves  or  layers,  placed  side  by  side.  Some  of  the  convolutions  are 
short,  others  long;  they  present  numerous  varieties  in  the  manner 
of  joining  each  other.  Owing  to  the  narrowness  of  the  fissures  be- 
tween them,  they  are  closely  packed  together,  so  that  the  lateral  sur- 
faces of  each  one  are  suited  to  such  as  are  contiguous ; occasionally, 
there  is  a departure  from  this  rule. 

The  surface  of  the  convolution,  by  which  we  mean  not  only  the 
most  exterior  periphery  of  the  cerebrum,  but  also  the  surface  formed 
by  the  fissures  to  their  very  bottom,  is  covered  by  cineritious  neurine 
or  matter  of  about  one  or  two  lines  in  thickness. 

Within  the  periphery  of  the  cerebrum,  the  mass  of  medullary 
neurine  or  matter  is  very  considerable,  and  is  of  an  ovoidal  shape. 
This  ovoid  is  called  the  Centrum  Ovale  of  Vieussens,  and  is  brought 
fairly  into  view  by  making  a horizontal  cut  through  the  hemispheres, 
two  inches  below  their  summit. 

• 

In  proceeding  with  the  anatomy  of  the  cerebrum  from  its  base 
upwards,  the  following  is  the  order  or  succession  of  parts  in  its 
structure:*  In  advance  of  the  pons  varolii,  and  springing  from  it, 
there  are  two  divergent  medullary  trunks,  one  on  each  side,  which 
run  forwards,  and  are  lost  in  the  medullary  substance  of  the  cere- 
brum. These  trunks  are  the  crura  cerebri,  upon  the  upper  surface 
of  each  are  two  protuberances:  the  posterior  is  the  thalamus  nervi 
optici,  and  the  anterior  is  the  corpus  striatum.  Each  crus  cerebri, 
having  penetrated  into  the  substance  of  its  respective  hemisphere, 
expands  by  a multiplication  of  the  filaments  composing  it,  so  as  to 
constitute  the  principal  bulk  of  the  hemisphere.  These  filaments 
may,  indeed,  be  traced  very  satisfactorily  in  almost  every  direction 
towards  the  periphery  of  the  cerebrum,  where  they  terminate  in  the 
convolutions,  their  extremities  being  covered  by  the  cineritious 
matter  there.  The  arrangement  is  best  seen  by  scraping  with  a 
knife  along  the  base  of  the  brain,  especially  when  the  latter  has  been 
hardened  in  spirits  of  wine,  and  it  is  constituted  by  what  are  called, 
by  MM.  Gall  and  Spurzheim,  the  diverging  fibres  of  the  brain. 

The  point  is  not,  indeed,  entirely  settled  that  the  diverging  filaments 
end  in  the  convolutions,  or  do  not  rather  afterwards  inflect  or  double 
on  themselves,  and  pass  inwards  again  to  the  middle  line  of  the  brain, 


Anat.  Atlas  Figs,  534,  536. 


THE  CEREBRUM. 


389 


forming,  by  their  convergence,  the  corpus  callosum.  At  all  events, 
the  fact  is  quite  demonstrable,  that  as  the  under  and  lateral  portions 
of  the  hemispheres  consist  in  diverging  filaments,  arising  in  and  from 
the  crus  cerebri,  so  the  upper  portion  and  the  corpus  callosum,  con- 
sist in  filaments  which  arise  in  the  adjoining  convolutions,  and  collect 
towards  the  middle  line  of  the  corpus  callosum,  where  they  adhere 
to  the  congeneric  filaments  of  the  other  side. 

The  arrangement,  in  the  most  simple  conception  and  illustration 
of  it,  would  be  exemplified  by  folding  a strip  of  cloth  double  on 
itself,  so  as  to  convert  it  into  a loop ; the  under  part  of  the  loop 
would  then  represent  the  diverging  fibres  of  the  cerebrum  and  the 
upper  part  the  converging  fibres,  or  corpus  callosum : it  being  at 
the  same  time  borne  in  mind  that  the  continuation  of  the  two  orders 
of  fibres  into  one  another  in  the  brain,  is  not  so  fully  ascertained  as 
would  be  represented  by  this  model. 

Between  these  two  orders  of  fibres  there  is  a horizontal  cleft  or 
interval.  This  interval  is  the  lateral  ventricle  of  the  hemisphere, 
which  may  be  got  into  under  the  posterior  margin  of  the  corpus 
callosum,  from  its  being  open  there,  or  rather  only  closed  by  an  ad- 
hesion of  the  membranes,  which  is  easily  lacerated. 

The  preceding  is  intended  as  a mere  outline  or  base  of  the  de- 
scriptive anatomy  of  the  cerebrum.  The  following,  therefore,  may 
be  considered  as  the  detailed  account : — 

The  Crura  Cerebri  are  rounded  below' ; are  about  eight  lines 
long,  and  increase  in  their  transverse  diameter  as  they  advance ; 
their  vertical  diameter  is  about  ten  lines.  They  mutually  diverge, 
beginning  from  their  roots,  and  are  separated  by  a deep  fissure, 
considered  as  a repetition  of  that  on  the  front  of  the  medulla  ob- 
longata. Above  this  fissure  is  the  third  ventricle  of  the  brain,  which 
itself  is  a repetition  of  the  middle  fissure  on  the  posterior  face  of  the 
medulla  oblongata.  The  surface  of  the  crura  is  marked  by  super- 
ficial furrow's,  running  longitudinally ; and  about  two  lines  before 
the  tuber  annulare,  by  a transverse  fasciculus  of  medullary  matter  or 
white  neurine,  very  slightly  elevated : the  optic  nerves  also  cross 
them  obliquely  at  their  fore  part. 

In  regard  to  texture,  the  crus  cerebri  presents,  on  its  under  sur- 
face, a medullary  layer  of  two  lines  in  thickness ; to  this  succeeds 
a parcel  of  cineritious  matter,  which,  on  being  removed,  is  followed 

Vol.  II.— 34 


390 


NERVOUS  SYSTEM. 


by  a mixture  of  both  cineritious  and  white  matter,  more  abundant 
than  either  of  the  preceding. 

The  Tuber  Cinereum,  or  Pons  Tarini,  is  a portion  of  the  under 
surface  of  the  crura  cerebri,  at  the  floor  of  the  third  ventricle.  It 
is  continuous  in  front  with  the  anterior  margin  of  the  corpus  cal- 
losum, forms  the  floor  of  the  third  ventricle,  and  is  composed,  as  its 
name  implies,  of  cineritious  neurine. 

The  Eminentice  Mammillares,  or  Corpora  Albicantia,  are  two 
small  bodies,  one  on  each  side,  about  the  size  of  a French  pea. 
They  are  situated  near  the  anterior  extremities  of  the  crura  cerebri, 
on  their  internal  faces,  and  almost  in  contact  with  each  other.  Their 
texture  is  medullary  without,  and  cortical  within. 

The  Infundibulum  is  placed  immediately  before  the  eminentiae 
mammillares.  It  is  a flattened  conoidal  body,  half  an  inch  long, 
with  its  base  upwards,  and  its  apex  going  downwards  and  fonvards. 
It  is  formed  of  cineritious  matter.  Most  generally  its  base  is  hol- 
low, and  opens  into  the  third  ventricle,  but  its  point  is  closed.  J.  F. 
Meckel,  hoAvever,  asserts  that  a communication  exists  entirely  through 
it,  from  the  pituitary  gland  to  the  third  ventricle,  and  that  he  has 
frequently  proved  this  by  passing  air  or  liquids  from  the  gland,  though 
the  experiment  does  not  succeed  when  he  attempts  the  injection 
from  the  third  ventricle. 

In  front  of  the  infundibulum  the  optic  nerves  unite,  after  having 
crossed  obliquely  the  crura  cerebri  from  without  inwards  and  for- 
wards. In  this  passage,  where  they  reach  the  middle  of  the  crura, 
and  at  the  internal  border  of  the  same,  they  come  in  contact  with 
the  tuber  cinereum,  from  which  they  get  a few  filaments;  but  of 
this,  more  hereafter. 

The  Pituitary  Gland  ( Glandula  Pituitaria ) is  situated  in  the  Sella 
Turcica,  and  is  covered  so  completely  by  the  dura  mater,  that  only 
a small  aperture  is  left  for  the  point  of  the  infundibulum  to  pass 
through  and  to  adhere  to  it.  It  is  an  ovoidal  body,  the  greatest  dia- 
meter of  which  is  transverse,  and  amounts  to  six  lines.  It  is  par- 
tially divided,  so  as  to  give  the  appearance  of  two  lobe^,  of  which 
the  anterior  is  much  the  larger.  It  is  hard  and  cineritious,  with  a 


THE  CEREBRUM. 


391 


small  quantity  of  medullary  matter  within.  In  either  side  of  it  there 
is  a depression  from  which  leads  a small  canal  towards  the  place 
where  the  infundibulum  joins  it ; the  two  canals  are,  in  the  latter 
place  united  into  one.  In  some  very  rare  cases,  gritty  matter  has 
been  found  in  it,  as  there  is  in  the  pineal  gland.  It  is  also  sur- 
rounded by  pia  mater. 

The  Thalami  Optici,  called,  by  Gall,  the  Posterior  Ganglions  of 
the  brain,  ( Ganglia  Postica,)  are  amongst  the  most  conspicuous 
parts  of  the  internal  structure  of  the  cerebrum,  and  are  two  in 
number,  one  for  either  side.  They  are  situated  on  the  superior  face 
of  the  crura  cerebri,  are  about  an  inch  and  a half  long  from  behind 
forwards,  and  about  eight  or  ten  lines  broad  and  deep. 

The  thalami  are  convex  above  and  internally.  At  the  junction 
of  these  two  surfaces  is  observed  a medullary  line,  described  under 
the  name  of  peduncle  of  the  pineal  gland.  Their  posterior  extre- 
mity is  likewise  convex,  and  is  divided  into  three  rounded  promi- 
nences : one  is  above  the  other  two,  and  is  the  Tuberculiim  Posterius 
Superius;  the  second  is  below  and  within,  ( Corpus  Geniculatum  In- 
ternum,) and  the  third  is  below  and  external,  ( Corpus  Geniculatum 
Externum.)  There  is  a fourth  tubercle  ( Tuberculura  Anterius) 
which  is  situated  in  front  on  tire  upper  convex  surface  of  the  thala- 
mus ; it  is  produced  by  the  fan-like  termination  of  a large  medullary 
fasciculus  which  comes  from  the  eminentia  mammillaris. 

The  thalami  are  somewhat  flattened  on  the  middle  of  their  con- 
vex internal  surface,  and  adhere  there  to  each  other  by  a layer  of 
cineritious  substance,  called  Commissura  Mollis.  When  the  brain 
is  very  slightly  advanced  in  putrefaction,  or  has  been  made  soft  by 
dropsy,  this  junction  scarcely  seems  to  exist  at  all. 

The  thalami  are  medullary  on  the  surface  presented  to  the  ven- 
tricles of  the  brain,  but  within  they  are  a mixture  of  cineritious  with 
medullary  matter.  The  fibres  of  the  medullary  are  very  intimately 
blended  with  the  crura  cerebri,  and  radiate  from  within  towards  the 
circumference  of  the  brain:  some  of  them  are  placed  in  layers,  and 
are  connected  with  the  tubercula  quadrigemina. 

The  Tubercula  Quadrigemina  (or  the  JYates  et  Testes)  are  situ- 
ated on  the  superior  face  of  the  crura  cerebri,  and  just  behind  the 
thalami  nervorum  optieorum.  A very  complete  view  of  them  is 
obtained  by  separating  the  posterior  lobes  of  the  cerebrum,  and  by 


392 


NERVOUS  SYSTEM. 


paring  off  the  vermis  superior  cerebelli.  Though  the  name  implies 
four  distinct  prominences,  yet  they  are  formed  from  a common  mass 
of  nine  or  ten  lines  square,  on  the  posterior  surface  of  which  these 
prominences  arise.  They  are  in  pairs,  and  are  separated  from  one 
another  by  a crucial  depression.  The  largest,  or  upper  pair,  is  the 
Nates,,  the  lower  pair  the  Testes.  The  external  surface  of  these 
bodies  is  medullary,  and  within  they  are  cineritious.  From  the 
Nates  there  proceeds  a considerable  medullary  fasciculus,  which 
runs  forward  to  join  the  Corpus  Geniculatum  Internum  on  the  in- 
ternal posterior  face  of  the  thalamus  nervi  optici ; there  proceeds 
also  from  them  a second  fasciculus,  which  either  joins  the  optic 
nerve  itself,  or  the  contiguous  part  of  its  thalamus.  The  Testes 
receive,  at  their  lower  end,  the  valve  of  the  brain ; and  there  also 
proceeds  from  them  a large  fasciculus  of  medullary  matter,  which 
joins  the  Corpus  Geniculatum  Externum  of  the  optic  thalamus.. 

The  Corpora  Striata,  or  the  Ganglia  Cerebri  Antica,  also  two  in 
number,  one  for  each  side  or  hemisphere  of  the  brain,  are  situated 
before  the  thalami  optici,  at  the  bottom  of  the'  lateral  ventricles. 
They  are  about  two  and  a half  inches  long,  convex  on  their  upper 
surface,  and  eight  lines  broad  at  their  front  part,  but  taper  very  gra- 
dually to  a point  behind.  They  are  about  four  lines  apart  in  front, 
and  are  separated  there  by  the  septum  lucidurn,  but  their  posterior 
extremities  diverge  from  each  other,  so  as  to  admit  the  thalami  optici 
between  them. 

The  surface  of  the  corpus  striatum,  is  cineritious,  but  within  it 
consists  of  cineritious  and  of  medullary  matter,  placed  in  layers 
which  alternate  with  each  other.  These  layers  are  arranged  in  a 
crescentic  manner,  so  as  to  present  the  convexity  upwards  and  the 
concavity  downwards.  The  medullary  substance  is  a continuation 
of  that  of  the  crus  cerebri  and  of  the  optic  thalamus.  It  enters  at 
the  posterior  inferior  part  of  the  corpus  striatum,  and  immediately 
divides  into  three  layers,  placed  one  above  the  other,  and  of  which 
the  two  inferior  are  more  narrow  and  short  than  the  superior.  The 
upper  layer,  in  its  progress  forwards,  is  interrupted  by  a body  ot 
cineritious  substance,  which  occasions  it  to  divide  into  a multitude 
of  distinct  radiated  fibres.  The  same  circumstance  attends  the  other 
layers,  but  in  a more  limited  degree.  The  medullary  matter  of  the 
corpus  striatum  may  then  be  traced,  in  all  directions,  into  the  hemis- 
phere of  the  brain.  The  cineritious  substance  of  the  corpus  striatum 
is  abundant,  and  is  divided  by  some  anatomists  into  two  kinds,  one 


THE  CEREBRUM. 


393 


of  a light  gray,  and  another  of  a darker  colour.  The  first  forms  the 
middle  and  inferior  part  of  the  corpus  striatum ; the  second  is  in 
greater  quantity,  and  is  found  principally  above  and  between  the 
two  upper  layers.  Such  is  the  general  plan  of  the  structure  of  the 
corpus  striatum ; but,  it  should  also  be  understood,  that  a close  in- 
tertexture exists  between  its  medullary  and  cineritious  matter. 

The  most  satisfactory  way  of  exposing  the  structure  of  the  corpus 
striatum,  is  to  scrape  off  its  under  surface,  in  tracing  its  medullary 
matter  from  the  crus  of  the  cerebrum,  and  through  the  optic  thala- 
mus. It  will  then  be  seen,  that  the  medullary  substance  of  the  crus 
reaches  the  posterior  inferior  part  of  the  corpus  striatum,  and  is  imme- 
diately invested  in  the  greater  part  of  its  circumference  with  cineritious 
matter,  it  then  begins  to  expand  after  the  manner  of  a fan  into  fila- 
ments. These  filaments  or  fasciculi  penetrate  the  cineritious  matter 
in  various  directions,  besides  those  just  detailed.  A particular  ex- 
position of  them  is  given  by  Gall  and  Spurzheim,  in  their  anatom) 
of  the  brain. 

The  Taenia  Striata  is  placed  in  the  angle  formed  between  the 
internal  margin  of  the  Corpus  Striatum,  and  the  external  one  of 
the  Thalamus  Opticus,  wdiere  these  twro  bodies  are  in  contact  and 
continuous  with  one  another.  It  is  a small  medullary  band,  not  a 
line  in  breadth,  commencing  near  the  anterior  crus  of  the  fornix, 
with  w'hich  it  is  connected  frequently  by  filaments ; and  observing 
the  curved  course  of  the  fissure  in  which  it  is  placed,  it  goes  to  the 
posterior  end  of  the  corpus  striatum,  and  even  beyond  it  in  most 
cases,  by  uniting  itself  to  the  top  of  the  Cornu  Ammonis. 

The  Corpus  Callosum.* — When  the  fissure  between  the  hemi- 
spheres of  the  cerebrum  is  widely  separated,  or  when  the  superior 
part  of  the  hemisphere  is  cut  away  on  a level  with  the  bottom  of  the 
fissure,  the  Corpus  Callosum,  a medullary  layer,  as  stated,  is  brought 
fully  into  view.  This  body  unites  the  medullary  mass  of  the  two 
hemispheres,  and  is  a large  commissure.  It  occupies  about  two- 
fifths  of  the  long  diameter  of  the  brain,  being  nearer  to  its  anterior 
than  to  its  posterior  end,  and  is  about  eight  lines  broad ; increasing, 
however,  somewhat  in  breadth  posteriorly.  The  lateral  half  of  it, 
on  either  side,  is  concealed  by  the  hemisphere  overlapping  it,  but  is 

* Anat.  Atlas,  Fig.  535. 

34* 


394 


NERVOUS  SYSTEM. 


prevented  from  adhering  by  a horizontal  fissure*,  which?  extends  from 
one  end  to  the  other.  It  has  an  arched  form,  being  oonvex  above 
and  concave  below.  Its  thickness  is  uniformly  about  three  lines, 
with  the  exception  of  its  anterior  and  its  posterior  margin,  which 
are  more.  Just  above  the  horizontal  fissure  there  exists  a longitu- 
dinal layer  of  white  neurine  running  from  one  end  to  the  other  of  the 
fiat  surface  of  the  hemisphere,  described  by  Mr.  Solly.* 

The  middle  line  of  its  upper  surface  is  marked  out  from  one  end 
to  the  other  by  a very  slight  depression,  the  Raphe ; on  each  side  of 
which  there  is  a very  small  linear,  elevation  of  the  same  extent,  but 
slightly  curved  inwards  towards  its  fellow.  From  these  longitudinal 
lines  there  proceed  outwardly  transverse  ones,  having  a filamentous 
appearance.  At  the  anterior  and  posterior  ends  of  the  corpus  callo- 
sum, the  fibres  are  somewhat  curved  and  radiate  towards  the  peri- 
phery of  the  brain.  Other  longitudinal  lines  also  exist  on  the  surface 
of  the  corpus  callosum,  but  they  are  not  seen  with  equal  facility. 
The  anterior  extremity  of  the  corpus  callosum  is  rounded  off,  and 
bent  downwards  towards  the  basis  of  the  brain,  in  such  a manner  as 
to  present  backwards  its  concavity  ; which  thus  embraces  the  fore 
part  of  the  corpora  striata,  and  closes  the  lateral  ventricles  at  this 
point.  The  posterior  end  of  the  corpus  callosum  is  rounded  also, 
and  continuous  with  the  fornix  and  with  the  cornu  ammonis. 

By  examining  the  Corpus  Callosum  from  below,  or  by  looking  at 
its  relative  situation  and  shape  on  a hemisphere  which  is  accurately 
separated  from  its  fellow  in  the  middle  line,  it  will  be  seen  that  its 
lower  surface  is  very  concave,  being  highly  arched  from  before  back- 
wards ; that  it  forms  the  roof  of  the  lateral  ventricles,  and  that  this 
surface  of  it  is  about  two  inches  in  its  transverse  diameter,  and, 
therefore,  more  than  twice  as  broad  as  the  upper  surface. 

The  Fornix,f  ( Trigone  Cerebral , of  the  French)  is  placed  imme- 
diately below  the  corpus  callosum.  It  is  a triangular  body  of 
medullary  neurine  or  matter,  the  base  of  which  is  behind  and  the 
apex  in  front.  It  is  about  an  inch  and  a half  long  in  its  body,  and 
one  inch  wide  at  its  base.  It  is  the  latter  part,  which,  lying  imme- 
diately beneath  the  posterior  end  of  the  corpus  callosum,  is  con- 
tinuous with  it,  and  causes  the  fornix  to  be  considered  as  a part  of 
the  same  structure  with  the  corpus  callosum.  These  two  bodies, 


Anatomj’  of  Brain,  1836. 


t Anat.  Atlas,  Fig.  543. 


THE  CEREBRUM. 


395 


which  may  be  compared  to  a sheet  of  medullary  matter  doubled  on 
itself,  have  their  surfaces  in  contact  for  a short  distance  behind,  the 
fornix  afterwards,  by  advancing  and  keeping  itself  in  close  contact 
with  the  thalami  nervorum  opticorum,  which  are  just  below  it,  di- 
verges more  and  more  from  the  under  surface  of  the  corpus  callosum. 
It  conceals  the  upper  surface  of  the  thalami  except  their  external 
margins,  and,  having  reached  their  anterior  extremities,  its  apex 
descends  towards  the  basis  of  the  brain. 

The  body  of  the  fornix  is  about  a line  thick,  but  at  its  anterior  ex- 
tremity, it  becomes  somewhat  cylindrical,  and  is  divided  into  two 
columns  or  legs,  called  Crura  Fornicis  Anteriora.  Each  of  these 
crura,  in  descending  adheres  to  the  anterior  extremity  of  the  tha- 
lamus of  that  side,  and,  getting  finally  below  it  into  the  floor  of  the 
third  ventricle,  it,  after  a course  slightly  curved,  joins  the  cortical 
substance  of  the  Eminentia  Mammillaris.  Santorini,  aware  of  this 
junction,  considered  the  eminentiae  as  a part  of  the  fornix,  and, 
therefore,  called;  them  Bulbi  Fornicis. 

The  fornix  has  other  attachments  of  a more  complex  description, 
which  the  anatomist  should  attend  to,  as  they  serve  to  indicate  the 
modes  of  intercourse  between  the  several  parts  of  the  cerebrum.  Its 
fibres  having  reached,  and  probably  formed,  the  eminentia  mammil- 
laris, one  fasciculus  of  them  ascends  from  thence  along  the  internal 
face  of  the  optic  thalamus,  invested  by  the  cineritious  matter  of  the 
latter,  and  spreads  itself  above  like  a fan,  and  forms  the  tuberculum 
anterius : a second  fasciculus  from  the  same  point,  having  divided 
into  two,  after  going  a short  distance,  sends  one  division  backwards 
along  the  upper  internal  face  of  the  optic  thalamus,  to  join  the  pe- 
duncle of  the  pineal  gland,  and  the  other  division,  wdiich  is  more 
anterior,  runs  to  join  the  taenia  striata;  the  third  fasciculus  from  the 
eminentia  mammillaris,  being  covered  by  the  optic  nerve,  goes  out- 
wards and  backwards  to  terminate  in  the  thalamus. 

The  posterior  margin,  or  the  base  of  the  fornix,  besides  running 
into  the  corpus  callosum,  has  the  angle  on  each  side  elongated  so 
as  to  rest  upon  and  to  join  the  upper  end  of  the  cornu  ammonis. 
The  angle,  being  continued,  then  follows  the  winding  course  of  the 
latter,  adhering  to  its  posterior  margin,  but  hanging  loosely  over 
the  anterior.  This  loose  edge  or  continuation  of  the  external  mar- 
gin of  the  fornix  is  the  Taenia  Hippocampi,  or  Corpus  Fimbriatum 
of  the  Lateral  Ventricle.  The  elongations  of  the  posterior  angles  are 
called  Crura  Posteriora  Fornicis.  In  the  brains  of  individuals  who 


396 


NERVOUS  SYSTEM. 


have  suffered  from  general  dropsy,  one  frequently  finds  the  fornix 
narrower  than  usual,  and  in  its  middle  a fissure  which  separates 
almost  completely  its  two  halves. 

As  the  fornix  is  fitted  to  the  upper  surface  of  the  optic  thalami, 
it  is  of  course  concave  below  and  convex  above,  or  resembles  a 
triangular  arch  resting  upon  its  three  points  or  angles.  Owing  to 
some  misunderstanding  of  the  original  Greek  word  -^xx «Je5,  which, 
according  to  the  interpretation  of  Sabatier,  means  a vault,  and  there- 
by expresses  the  whole  body,  anatomists,  with  the  exception  of  him 
have  generally  supposed  the  striated  under  surface  of  the  fornix  to 
be  meant  by  it,  and  have  therefore  called  the  surface  Lyra,  in  which 
mistake  one  has  followed  another. 

The  Septum  Lucidum  is  a partition  placed  vertically  in  the  mid- 
dle line  of  the  brain,  and  extends  from  the  corpus  callosum  above 
to  the  fornix  below.  It  is  of  a triangular  shape,  but  irregularly  so, 
being  much  broader  before  than  it  is  behind,  and  having  its  edges 
so  incurvated  as  to  fit  the  bodies  against  which  it  is  applied. 

The  septum  lucidum  is  formed  by  two  laminse  placed  side  to  side, 
but  not  adhering  to  each  other,  and  leaving,  therefore,  an  interval 
between  them,  called  the  Ventriculus  Septi,  or  the  fifth  ventricle. 
Each  of  these  laminae  consists  of  two  layers:  the  internal  is  medul- 
lary substance,  continuous  with  that  of  the  corpus  callosum  and  of 
the  fornix;  and  the  external  is  a layer  of  cineritious  substance.  The 
cavity  is  about  an  inch  and  a half  long  by  a line  wide,  and  is  nar- 
rower in  the  middle  than  at  either  extremity.  It  is  lined  by  a de- 
licate serous  membrane,  which  becomes  manifest  when  the  halitus 
that  naturally  covers  its  surface  is  accumulated  into  a body  of  water. 
It  is  generally  supposed  to  be  insulated  or  completely  shut  up,  yet 
occasionally  it  has  be£n  found  elongated  in  front,  towards  the  space 
between  the  anterior  commissure  and  the  crura  fornicis,  and  to  com- 
municate there  with  the  third  ventricle.* 

The  Pineal  Gland  ( Glandula  Pinealis,  Conarium ) is  placed  be- 
neath the  posterior  margin  of  the  fornix,  upon  the  superior  of  the 
tubercula  quadrigemina,  or  the  nates.  It  is  an  oblong  conoidal 
body,  the  longest  diameter  of  which  is  transverse,  and  amounts  to 
three  or  four  lines,  while  the  short  diameter  is  near  three  lines. 


* J.  F.  Meckel. 


THE  CEREBRUM. 


397 


These  diameters  are,  however,  sometimes  reversed.  The  substance 
of  the  pineal  gland  is  cineritious  and  of  a reddish  colour.  At  its 
inferior  part  there  is  a small  cavity,  sometimes  lined  with  medullary 
matter,  and  the  orifice  of  which  looks  towards  the  third  ventricle. 

This  body  is  connected  to  the  adjacent  parts  by  several  cords. 
From  its  bottom  there  proceeds,  on  each  side,  the  long  medullary 
filament,  called  its  peduncle,  which  runs  along  the  upper  internal 
face  of  the  thalamus  opticus,  and,  as  observed,  joins,  or  is  conti- 
nuous with,  one  of  the  filamentous  processes  from  the  Eminentia 
Mammillaris  as  connected  with  the  anterior  crus  of  the  fornix. 
From  its  base  there  proceeds  a transverse  lamina  of  medullary  mat- 
ter, called  the  Posterior  Commissure  of  the  brain,  which  first  ad- 
vances forwards,  and  then  recedes,  so  as  to  be  in  some  measure 
doubled  on  itself.  This  lamina,  at  either  end,  is  united  to  the  up- 
per posterior  part  of  the  corresponding  optic  thalamus,  and  by  its 
lower  margin  runs  into  the  superior  edge  of  the  tubercula  quadri- 
gemina. 

Frequently,  withirejhe-  pineal  gland,  and  sometimes  on  its  sur- 
face, there  is  an  accumulation  of  calcarious  matter,  the  Acervulus 
Cerebri,  that  appears  about  the  sixth  year  of  life,  and  continues  for 
ever  afterwards.  It  is  variable  both  in  quantity  and  in  its  mode  of 
concretion,  for  sometimes  there  are  only  a few  atoms  of  grit,  scarcely 
distinguishable  by  the  feel;  while,  on  other  occasions,  it  is  collected 
into  a body  of  irregular  shape,  and  more  than  a line  in  diameter. 
The  pieces  of  which  the  acervulus  consists  are  sometimes  united  by 
cellular  substance  and  enclosed  in  a sac.  The  chemical  analysis 
presents  phosphate  of  lime  in  large  proportion,  carbonate  of  lime, 
and  animal  matter. 

There  are  some  analogies  of  texture  between  the  exterior  of  the 
Pineal  Gland  and  the  Glandulse  Pacchioni,  as  the  latter  appear  on 
the  different  processes  of  pia  mater.  This  analog}'  is  closer  than 
that  of  Pacchioni’s  glands  in  the  longitudinal  sinus,  with  those  on 
the  pia  mater. 

A reflection  of  pia  mater,  called  Velum  Interpositum,  separates 
the  pineal  gland  from  the  fornix,  and  the  fornix  from  the  thalami 
nervorum  opticorum. 


398 


NERVOUS  SYSTEM. 


Of  the  Ventricles  of  the  Brain.* 

These  cavities  are  four  in  number:  two,  called  lateral,  are  placed 
each  one  in  its  respective  hemisphere  of  the  cerebrum,  a third  is  be- 
tween the  two  thalami,  and  the  fourth  under  the  cerebellum.  They 
have  all  been  alluded  to,  but  only  incidentally. 

The  two  Lateral  Ventricles  (Ventriculi  Later  ales)  are  horizontal 
cavities,  or  fissures,  of  an  extremely  irregular  shape,  in  the  very 
centre  of  the  hemispheres,  being  the  interval  between  the  diverging 
and  converging  filaments  of  the  cerebrum.  They  are  separated  from 
each  other  only  by  the  septum  lucidum ; are  covered  over  by  the 
corpus  callosum,  and  have  the  fornix,  thalami  optici,  and  corpora 
striata  for  a floor.  Each  one  consists  in  a body  or  principal  cavity, 
and  three  processes,  called  cornua.  The  body  has  been  sufficiently 
described  in  speaking  of  the  parts  which  constitute  its  parietes ; but 
the  processes  are  yet  to  be  considered. 

The  Cornua,  from  their  position,  are  nan\ed  Anterior,  Posterior, 
and  Lateral  or  Inferior.  The  Anterior  is  a very  small  space  be- 
tween the  anterior  extremity  of  the  corpus  striatum  and  the  opposite 
surface  of  the  hemisphere,  and  has  nothing  in  it  particularly  deserv- 
ing of  notice.  The  Posterior  Cornu  extends  from  the  base  of  the 
fornix  to  the  distance  of  an  inch  or  more  in  the  substance  of  the 
posterior  lobe  of  the  cerebrum.  Its  cavity  is  conoidal,  somewhat 
curved,  with  its  convexity  outwards,  and  is  six  or  seven  lines  in 
diameter  at  its  base.  Its  internal  side  is  furnished  with  an  oblong 
eminence  called  Hippocampus  Minor,  or  Ergot,  from  its  resemblance 
to  a cock’s  spur,  but  its  size  and  form  are  somewhat  variable.  When 
this  eminence  is  cut  through  transversely,  it  is  easy  to  see  that  it  is 
formed  by  a convolution  of  the  posterior  lobe  projecting  into  the  pos- 
terior cornu.  The  convolution  is  covered  by  medullary  matter  on 
the  side  of  the  ventricle,  and  of  course  by  cineritious  on  the  side  ot 
the  periphery  of  the  brain,  and  is  the  bottom  of  an  anfractuosity. 

The  Inferior,  Middle,  or  Lateral  Cornu,  of  the  Lateral  ventricle 
is  situated  in  the  middle  lobe  of  the  cerebrum.  It  commences  at 
the  posterior  angle  of  the  fornix,  and  winds  downwards  and  for- 
wards in  a semicircle  towards  the  fissure  of  Sylvius,  presenting  its 


Anat.  Atlas,  Figs.  541  to  546,  inclusive. 


VENTRICLES  OF  CEREBRUM. 


399 


convexity  outwards,  and  its  concavity  within.  Its  floor  is  furnished 
in  its  whole  length  with  an  elevated  ridge,  the  surface  of  which  is 
semi-cylindrical.  This  ridge  is  the  Cornu  Ammonis,  or  Hippocampus 
Major,  and  increases  somewhat,  both  in  breadth  and  elevation,  as  it 
winds  down  the  process  of  the  ventricle.  Its  lower  or  anterior  ex- 
tremity is  terminated  by  two  or  three  small  tubercles,  and  is  the  Pes 
Hippocampi.  Occasionally  the  Hippocampus  Major  is  marked  off 
by  a middle  longitudinal  fissure  into  two  elevations,  of  which  the 
external  is  the  smaller.  On  its  concave  side  there  is  the  thin  edge 
of  medullary  matter,  continuous  with  the  external  margin  of  the  fornix. 
The  extremity  of  a knife  handle  may  be  insinuated  for  a short  dis- 
tance between  this  edge  and  the  Hippocampus;  it  ceases  about  half 
way  down  the  latter,  and  in  the  natural  state  of  the  parts  is  concealed 
by  the  plexus  choroides.  This  edge  is,  as  mentioned  in  the  account 
of  the  fornix,  the  Tsenia  Hippocampi  or  Corpus  Fimbriatum  of  the 
lateral  ventricle.  Beneath  the  latter,  and  partially  covered  by  it, 
there  is  another  body,  which  presents  itself  in  the  form  of  a small 
cord  of  cineritious  matter,  not  quite  so  long  as  the  Tsenia,  and  is 
called  Fascia  Dentata,  from  being  divided  into  several  sections  by 
transverse  fissures,  which  give  it  a tooth-like  appearance. 

A transverse  incision  of  the  Hippocampus  Major  shows  that  it  is 
a body  of  cineritious  matter,  covered  on  its  surface  by  a thin  layer 
of  medullary  substance. 

When  the  fornix  is  separated  from  its  anterior  crura  and  turned 
over  backwards,  the  process  of  pia  mater,  called  Velum  Interposi- 
tum,  is  found  between  it  and  the  optic  thalami.  This  process  is 
of  a triangular  shape,  resembling  the  fornix,  and  is  about  the  same 
size ; it  is  insinuated  into  its  place  from  the  surface  of  the  brain, 
under  the  posterior  margin  of  the  corpus  callosum.  Its  lateral  mar- 
gins, which  project  beyond  the  corresponding  ones  of  the  fornix,  are 
formed  by  a congeries  of  convoluted  vessels,  constituting  the 
Plexus  Choroides. 

The  Plexus  Choroides,  may  be  traced  from  the  Pes  Hippocampi 
along  the  corpus  fimbriatum  to  its  position  on  the  margin  of  the 
velum  interpositum ; and  insinuates  itself  from  the  bottom  of  the 
cerebrum  between  the  pons  varolii  and  the  convolution  forming  the 
Hippocampus  Major ; but  when  it  reaches  the  anterior  end  of  the 
fornix  its  convoluted  character  ceases,  and  it  terminates,  on  each 
side,  in  a single  vein,  ( Vena  Galeni),  which  runs  from  before  back- 


400 


NERVOUS  SYSTEM. 


wards,  in  a straight  line,  near  the  middle  of  the  velum  interpositum. 
The  vein,  finally,  unites  with  its  fellow  to  form  a single  trunk,  which 
runs  into  the  fourth  sinus  of  the  dura  mater. 

This  Velum  Interpositum,  called  also  Tela  Choroidea,  adheres 
very  strongly  to  the  fornix  by  means  of  small  vessels : it  may  be 
raised  with  less  difficulty  from  the  thalami,  though  it  serves  to  keep 
the  third  ventricle  closed  above,  with  the  exception  of  the  part  just 
behind  the  crura  of  the  fornix,  where  the  third  and  the  lateral  ven- 
tricle communicate  by  the  foramen  of  Monro.  The  pineal  gland  is 
entangled  in  its  posterior  part,  being  placed  below  it,  and  is  generally 
torn  from  its  peduncles  when  the  tela  is  raised  up.  It  is  at  this 
point  that  the  tunica  arachnoidea  may  be  traced  into  the  cavity  of 
the  lateral  ventricles,  according  to  Bichat.* 

The  Plexus  Choroides,  which  vTas  stated  to  bound  the  Velum 
Interpositum  on  each  side,  and  to  descend  along  the  Hippocampus 
Major  to  the  fissure  of  Sylvius,  or  rather  to  ascend  from  this  point, 
and  to  terminate  in  the  vein  on  the  side  of  the  middle  line  of  the 
Velum,  is  narrow  at  its  termination,  but  increases  continually  in 
breadth  as  it  is  traced  towards  its  commencement.  The  middle 
part,  however,  where  it  makes  its  turn,  is  an  exception  to  this  rule, 
for  there  it  is  larger  in  every  wray  than  elsevdiere : its  vessels  being 
more  capacious  and  more  tortuous.  • Precisely  at  this  point  one  or 
more  vesicles  are  very  frequently  found,  considered  by  some  as  hyda- 
tids of  the  brain  ; in  some  cases  they  are  filled  with  calcarious 
matter  instead  of  with  water.  The  Glanduke  Pacchioni,  as  stated, 
also  prevail  at  this  margin. 

On  the  under  surface  of  the  Velum  Interpositum,  adhering  to  it, 
there  is  on  each  side  a small  venous  plexus  which  goes  from  before 
backwards,  and  terminates  in  the  vena  galeni,  near  its  junction  with 
its  fellow.  It  receives  the  blood  of  the  third  ventricle. 

There  is  also  the  same  sort  of  plexus  in  die  fourth  ventricle. 

Upon  the  removal  of  the  Velum  Interpositum,  or  its  elevation, 
the  whole  upper  surface  of  the  thalami  optici  is  exposed.  The  third 
ventricle  is  also  brought  into  view,  being  placed  immediately  between 
the  thalami  optici. 

* Some  doubts,  I have  mentioned  before,  may  be  reasonably  raised  on  this  point  of 
anatomy,  as  the  evidence  is  seldom  or  never  satisfactory  to  the  full  extent,  and  as 
such  an  arrangement  would  be  contradictory  to  that  of  the  tunica  arachnoidea  on  the 
surface  of  the  brain,  which  never  dips  into  fissures. 


VENTRICLES  OF  CEREBRUM. 


401 


The  Third  Ventricle,  (Ventriculus  Tertius ,)  is  a narrow  oblong 
cavity,  bounded  below  by  the  pons  Tarini,  crura  cerebri  and  the 
eminentiae  mammillares;  and  above  by  the  velum  interpositum  and 
the  fornix.  It  is  an  extension  of  the  posterior  middle  fissure  of  the 
medulla  oblongata  conducted  along  the  middle  of  the  pons  varolii. 
The  anterior  crura  of  the  fornix  are  at  its  fore  part,  and  just  before 
them  is  the  Anterior  Commissure  ( Commissura  Anterior.)  This 
body  is  a transverse  fasciculus  of  medullary  matter,  which  passes 
from  one  hemisphere  to  the  other  through  the  anterior  margins  of 
the  thalami  optici.  Its  middle  part  is  rounded  and  free,  but  its  ex- 
tremity penetrates  on  each  side  into  the  substance  of  the  anterior  in- 
ferior portion  of  the  corpus  striatum,  and  spreading  out  gradually 
describes  a curve  with  its  convexity  forwards,  which  terminates  near 
the  Pes  Hippocampi  of  the  inferior  cornu  of  the  lateral  ventricle. 
This  fasciculus,  in  penetrating  the  corpus  striatum,  does  not  mix 
with  its  substance,  but,  in  the  early  part  of  its  course,  goes  in  a canal 
formed  in  the  latter.  In  order  to  see  this  arrangement,  a part  of  the 
corpus  striatum  must  be  removed.  The  anterior  commissure  resem- 
bles a nerve  in  its  structure,  as  it  is  surrounded  by  a very  delicate 
sheath,  and  is  divided  into  fasciculi  of  fibres.  It  will  now  be  under- 
stood that  three  commissures  are  found  in  the  third  ventricle,  the 
Anterior  Commissure — the  Posterior  which  is  just  in  front  of  the 
Pineal  Gland,*  and  the  Soft  Commissure,  being  a cineritious  adhe- 
sion of  the  Thalami  at  their  middle. f 

Just  behind  and  below  the  anterior  commissure,  the  base  of  the 
infundibulum  opens  into  the  third  ventricle ; this  place  is  the  Iter  ad 
Infundibulum.  At  the  posterior  extremity  of  the  third  ventricle,  just 
below  the  posterior  commissure,  which  has  been  described  as  a pro- 
cess of  the  pineal  gland,  the  communication  exists  with  the  fourth 
ventricle.  This  passage  is  the  Aqueduct  of  Sylvius,  and  leads  ob- 
liquely downwards  and  backwards  under  the  valve  of  the  brain. 

The  third  ventricle  communicates  freely  with  the  lateral  ventricle 
through  the  aperture  called  the  Foramen  of  Monro,  which  is  situated 
precisely  at  the  place  where  the  plexus  choroides  terminates  ; that  is 
under  the  anterior  crus  of  the  fornix.  Doubts  have,  from  time  to 
time,  been  suggested  in  regard  to  the  natural  existence  of  this  com- 
munication; it  only  requires  a moderate  degree  of  accurate  observa- 
tion to  dispel  them : they  have  arisen,  probably,  from  the  aperture 

* See  Pineal  Gland. 

Vol.  II.— 35 


t See  Thalami. 


402 


NERVOUS  SYSTEM. 


being  shut  up  by  the  occasional  adhesion  of  the  plexus  choroides  to 
the  contiguous  surface  of  the  brain. 

The  Fourth  Ventricle  ( Ventriculus  Quartus,  Cerebelli ) has  been, 
in  a great  degree,  described  in  the  account  of  the  neighbouring  parts ; 
it  will,  therefore,  be  very  readily  understood  on  the  present  occasion. 
It  is  an  irregular  triangular  cavity,  the  base  of  which  is  downwards. 
It  is  bounded  in.  front  by  the  tuber  annulare,  and  the  medulla  ob- 
longata, behind  by  the  fundamental  portion  of  the  cerebellum,  and 
above  by  the  valve  of  the  brain  and  the  tubercula  quadrigemina;  it 
is  under  the  latter  that  the  communication  between  it  and  the  third 
ventricle  is  found.  Its  lateral  parietes  are  formed  by  the  medullary 
prolongations  from  the  cerebellum  to  the  tubercula  quadrigemina. 
This  cavity,  as  stated,  is  open  below,  when  that  portion  of  pia  mater 
is  removed,  which  passes  from  the  cerebellum,  to  the  medulla  ob- 
longata. 

From  what  has  now  been  said  of  the  connexion  of  the  pia  mater 
with  the  ventricles,  it  will  be  understood  that  as  their  surfaces  are 
covered  by  pia  mater,  and  the  removal  of  it  exposes  their  cavities, 
they  are  in  fact,  continuations  of  the  external  surface  of  the  brain. 
The  ventricles  are  generally  found  upon  death  to  contain  two  or 
three  tea-spoonsful  of  light  coloured  serum,  called  by  Magendie  the 
encephalo  spinal  fluid.  In  Williams,  examined  immediately  after 
his  execution,  August  9,  1839,  the  encephalo  spinal  fluid,  amount- 
ing to  from  two  to  three  drachms,  came  out  clear  and  abundant  from 
the  fourth  ventricle ; on  cutting  through  the  tunica  arachnoidea  which 
bounds  it  below. 


SECT.  VI. — OF  THE  NERVES  OF  THE  ENCEPHALON.* 

These  nervesf  are  designated  numerically,  from  before  backwards, 
and  also,  by  some  peculiarity  of  distribution  of  function.  This  nu- 

* The  more  improved  observations  of  modern  anatomists  having  pointed  out  the 
fallacy  of  considering  the  brain  as  the  source  of  the  spinal  marrow,  instead  of  the 
reverse  ; it  follows,  that  the  proper  order  of  describing  the  nerves  of  the  encephalon, 
is  successively  from  the  spinal  marrow.  I had  adopted  this  plan,  formerly,  but  cer- 
tain considerations  of  facility  in  study,  have  induced  me  to  abandon  it  after  some 
years  of  experience. 

t Anat.  Atlas,  Figs.  533,  547. 


NERVES  OF  THE  ENCEPHALON. 


403 


merical  arrangement  is  the  most  sanctioned  by  age  and  general  ad- 
mission, it  is  not,  however,  so  unexceptionable  as  to  avoid  all  ob- 
jections to  it;  improvements  have  therefore  been  suggested  from 
various  quarters,  founded  on  particular  anatomical  or  physiological 
considerations;  but  the  impnrvements  themselves  are  exposed  to  ob- 
jections as  strong  as  the  ancient  nomenclature.  For  example,  the 
innovators  are  not  agreed  in  regard  to  the  proper  number  of  nerves, 
nor  on  those  which  should  be  considered  distinct. from  each  other. 
Some  do  not  consider  the  olfactory  as  a nerve,  but  only  a ganglion ; 
some  consider  the  glosso  pharyngeal  and  par  vagum  as  but  one  nerve, 
while  others  speak  of  them  as  two.  Some  make  but  one  nerve  of 
the  third  and  sixth,  owing  to  their  common  distribution  to  the  mus- 
cles of  the  eye.  It  is  evidently  expedient,  under  these  circumstances, 
to  escape  a farrago  of  opinions,  by  adhering  to  the  most  received 
classification,  at  least,  till  the  ground  of  change  be  better  explored 
and  more  universally  acknowledged.  If  there  be  any  thing  of  in- 
calculable importance  to  the  comfort  of  students  and  scientific  men 
generally,  it  is  uniformity  of  language,  or  rather  conformity  to  a re- 
ceived standard  of  nomenclature.  The  only  justifiable  departure 
from  this  rule,  is  where  something  new  has  been  actually  discovered, 
a necessity  of  course  then  exists  for  giving  a new  name,  as  it  would 
not  do  to  take  the  appropriated  one  of  any  thing  else. 

The  Olfactory  Nerve  (First  Pair,  JYervus  Olfactorius , Par  Primum ,) 
is  situated  on  the  under  surface  of  the  anterior  lobes  of  the  brain, 
near  the  fissure  that  separates  the  hemispheres.  It  goes  forwards 
from  its  root,  and  also  converges  gradually  towards  its  fellow,  so  as 
to  reach  the  cribriform  plate  of  the  ethmoid  bone,  through  the  per- 
forations of  which  it  passes  out.  In  its  course,  it  is  lodged  in  a 
small  furrow  of  the  cerebrum,  by  which  pressure  upon  it  is  pre- 
vented. 

This  nerve  arises  by  three  medullary  fasciculi,  or  roots,  from  the 
basis  of  the  brain  at  the  corpus  striatum,  in  the  fissure  of  Sylvius, 
where  the  anterior  and  middle  lobes  join  each  other:  these  roots  are 
from  eight  to  twelve  lines  on  the  outer  side  of  the  infundibulum. 
The  roots  are  placed,  in  regard  to  each  other  diverging ; one  is  with- 
in, another  in  the  middle,  and  the  third  external.  The  external 
root  is  the  longest,  and  arises  from  the  extreme  posterior  margin  of 
the  anterior  lobe  by  its  last  convolution;  being  connected  with  the 
middle  lobe,  and  also  with  the  anterior  commissure  of  the  brain.  It 


404 


NERVOUS  SYSTEM. 


has  a curved  course  from  without  inwards,  the  concavity  of  which 
is  forwards,  and  the  convexity  backwards.  The  internal  root  is 
concealed  by  the  chiasm  of  the  optic  nerves,  and  arises  from  the  ad- 
jacent surface  of  the  anterior  lobe.  The  middle  root  comes  from 
the  posterior  margin  of  the  anterior  lobe  by  the  cribriform  surface, 
which  is  between  the  other  two  roots.  These  origins  emanating 
from  the  cortical  substance,  unite  to  form  a single  prismatic  cord, 
which  increases  in  size  as  it  advances  forwards,  and  consists  of  me- 
dullary and  cineritious  longitudinal  fibres  mixed  together. 

The  anterior  extremity  of  the  olfactory  nerve  is  swollen  out  into 
what  is  called  the  bulb,*  ( Bulbus ,)  and  sends  from  its  under  surface 
filaments,  which,  suirounding  themselves  with  a tunic  from  the  dura 
mater,  penetrate  into  the  nose,  and  spread  themselves  on  the  Schnei- 
derian membrane.  In  its  whole  length  it  is  exceedingly  soft  and 
pulpy,  till  it  gets  out  of  the  cranium. 

The  Optic  Nerve,  (Second  Pair,  JYervus  Opticus,  Par  Secundum) 
is  about  the  same  size  with  the  trigeminus.  It  arises  by  a broad 
flattened  root,  one  portion  of  which  comes  from  the  posterior  end  of 
the  thalamus  opticus,  and  another  from  the  testis  through  the  means 
of  a medullary  band  that  passes  from  the  latter,  towards  the  thalamus 
of  the  same  side.  From  this  point  the  optic  nerve  winds  forwards 
under  the  crus  cerebri,  adhering  to  it  and  forming  a connexion  with 
the  tuber  cinereum,  and  then  inclining  inwards  towards  its  fellow’. 
Its  adhesion  to  the  crus  is  considered  by  many  anatomists  as  another 
of  its  origins. 

The  optic  nerve,  having  reached  the  under  anterior  part  of  the 
third  ventricle,  adheres  so  closely  to  its  fellow  that  the  two  seem 
fused  together,  in  such  a way  that  there  is  no  line  of  separation  be- 
tween them.  This  junction  receives,  above  from  the  third  ventricle, 
some  medullary  filaments,  which  Meckel  feels  authorized  to  con- 
sider as  another  origin.  The  junction  presents  the  form  of  the  letter 
X,  and  is  called  the  chiasm  or  crossing  of  the  optic  nerves.  The 
most  distinguished  anatomists,  however,  have  laboured  in  vain  to 
settle  the  question  of  the  mode  of  junction ; some  believing  that 
there  was  only  a lateral  union,  others  that  the  nerve  of  one  side 
crossed  over  to  the  other  side,  and  others,  again,  that  the  decussa- 

* Many  anatomists  consider  this  as  a ganglion,  from  its  extreme  development  in 
the  sheep,  bullock,  horse,  (See.,  and,  therefore,  call  it  the  Olfactory  Ganglion.  Ro- 
lando.  Solly  on  the  Brain,  &c. 


NERVES  OF  THE  ENCEPHALON. 


405 


tion  occurred  only  with  some  of  the  fibres,  but  not  all.  Observa- 
tions, in  comparative  anatomy,  on  blindness,  and  indeed  on  every 
conceived  mode  of  elucidation,  have  been  resorted  to  without  pro- 
ducing a solution  of  the  problem ; but  the  discussion  of  their  merits 
would  require  too  much  space  for  the  present  work.* 

The  optic  nerves  as  they  approach  their  chiasm  become  more 
cylindrical,  and,  continuing  so  afterwards,  penetrate  into  the  orbits 
through  the  foramina  optica.  It  is  only  in  front  of  their  junction 
that  they  are  invested  by  a neurileme  ; which,  having  considerable 
firmness,  penetrates  into  their  interior,  and  divides  them  into  dis- 
tinct canals. 

The  Nervus  Motor  Oculi,  (Third  Pair,  Par  Tertium ,)  arises 
from  the  internal  face  of  the  crus  cerebri,  about  two  lines  in  ad- 
vance of  the  anterior  margin  of  the  tuber  annulare.  Its  roots  come, 
in  great  part,  from  the  cineritious  matter  which  is  found  on  the  sur- 
face of  the  crus,  and  may  be  traced  for  some  distance  upwards  and 
backwards  along  the  parietes  of  the  third  ventricle.  The  nerves  of  the 
opposite  sides  are  in  contact  for  some  distance  by  the  internal  faces 
of  their  roots,  but  do  not  adhere. f 

The  nervus  motor  oculi  proceeds  from  its  origin  towards  the 
external  margin  of  the  cavernous  sinus,  and,  penetrating  into  the 
orbit  through  the  sphenoidal  foramen,  it  is.  distributed  to  most  of  the 
muscles  of  the  eye-ball. 

The  Pathetic  Nerve,  (Fourth  Pair,  Nervus  Pathetieus , Par  Cere - 
brale  Quartum)  is  the  smallest  which  comes  from  the  encephalon, 
and  is  not  larger  than  a sewing  thread.  It  arises  by  two  filaments, 
or  roots,  from  the  upper  end  of  the  valve  of  the  brain,  just  below  the 
testis.  This  origin  is  soft,  and  easily  broken,  from  the  want  of  a 
neurileme  ; but  the  latter  is  soon  afterwards  furnished. 


* Mr.  Mayo,  of  London,  considers  the  posterior  part  of  the  junction  as  formed  of 
fibres,  making  a curve,  the  convexity  of  which  is  forwards  ; it  is  said  to  be  very 
distinct  in  the  mole,  which  has  no  other  optic  nerve.  My  own  examinations  have  re- 
suited  in  exhibiting  decussating  fibres- behind,  a junction  in  front  like  the  two  sides 
of  the  printed  letter  U,  and  a common  mass  in  the  centre. 

t Mr.  Solly  considers  this  nerve  to  arise  from  the  interior  of  the  pons  Varolii,  and 
to  be  connected  with  the  valve  of  Vieussens  by  some  fibres  from  the  latter,  going  into, 
the  crus  cerebri. 


35 


406 


NERVOUS  SYSTEM. 


The  nervus  patheticus  appears  on  the  base  of  the  brain,  between 
the  cerebellum  and  the  posterior  lobes  of  the  cerebrum,  at  the  ex- 
ternal margin  of  the  tuber  annulare.  It  then  goes  for  some  distance 
along  the  margin  of  the  tentorium  till  if  comes  near  the  posterior 
clinoid  process  : it  then  penetrates  into  a canal  of  the  dura  mater, 
and  reaches  the  orbit  of  the  eye  through  the  sphenoidal  foramen,  to 
be  distributed  on  the  superior  oblique  muscle. 

The  Nervus  Trigeminus,  (Fifth  Pair,  Par  Quintum , also  called 
Trifacial)  is  one  of  the  largest  among  those  that  proceed  from  the 
basis  of  the  brain,  and  emerges  from  the  side  of  the  pons  varolii, 
just  where  it  is  continuous  with  the  crus  cerebelli.  It  is  composed 
of  three  roots  : an  anterior,  a posterior,  and  a middle  ;*  of  which  the 
latter  is  much  the  largest. 

The  middle  root  is  about  a line  and  a half  in  breadth,  and  has  a 
passage  made  for  it  by  the  very  obvious  splitting  of  the  superficial 
fibres  of  the  pons  Varolii.  It  is  composed  of  thirty  or  forty  fasciculi, 
which  are  divisible  into  a hundred  or  more  fibres.  These  fasciculi 
may  be  traced  into  the  substance  of  the  pons  Varolii,  but  inter- 
sected by  the  transverse  fibres  of  the  latter,  in  the  direction  of  the 
fourth  ventricle.  When  they  have  come  near  the  latter,  they  may 
be  traced  thence  into  the  medulla  oblongata,  towards  the  fissure  that 
exists  between  the  corpus  olivare  and  restiforme.  It  is  at  this  point, 
that  the  greater  number  of  the  fibres  arise;  some  from  the  corpus 
olivare,  and  others  from  the  fissure. 

The  commencement  of  this  root  is  pulpy  and  destitute  of  fila- 
ments, and  is  surrounded  by  grayish  substance ; but  when  it  has  ad- 
vanced into,  the  pons,  it  is  surrounded  by  a fine  membrane,  and 
is  very  evidently  filamentous.  There  is  a successive  increase  in 
its  size,  from  its  commencement  till  it  is  ready  to  emerge  from  the 
pons,  when  it  becomes  somewhat  contracted,  and  immediately  after-, 
wards  increases  again  considerably  in  size.  It  then  enters  a canal 
of  the  dura  mater  at  the  fore  part  of  the  petrous  portion  of  the  tem- 
poral bone,  and  just  behind  the  cavernous  sinus.  This  canal  sets. 
but  loosely  about  it  at  first,  but  afterwards  it  adheres  to  the  surface 
of  the  nerve. 

The  middle  root  of  the  nervus  trigeminus,  in  the  upper  part  of 

* Santorini,  Obscrv.  Anat.  Vcnitia,  1724.  SoEinmering.  de  Corp.  Hum.  Fabrica, 
.ora.  iv.  Gall  and  Spurzheim,  Anat.  du  Csr-v. 


NERVES  OF  THE  ENCEPHALON. 


407 


the  canal  of  the  dura  mater,  preserves  its  fasciculated  appearance, 
and  many  small  filaments  are  interchanged  between  the  fasciculi, 
so  as  to  make  a complex  net-work.  But,  at  the  lower  part  of  this 
canal,  it  is  converted  into  a ganglion  of  a semi-lunar  shape,  with 
its  concavity  upwards,  being  about  six  or  eight  lines  in  length,  and 
one  and  a half  in  breadth.  This  body  called  the  Ganglion  of 
Gasser,  ( Ganglion  Semi-lunare,  Plexus  Gangliformis ,)  is  compact, 
and  has  its  fibres  very  much  matted  above,  but  below  they  assem- 
ble into  larger  and  more  distinct  fasciculi,  which  are  afterwards 
arranged  into  three  principal  trunks,'  departing  from  the  cranium 
through  different  foramina ; to  wit : through  the  sphenoidal  foramen, 
the  foramen  rotundum,  and  the  foramen  ovale. 

J.  F.  Meckel  asserts  that  the  filaments  of  the  plexus  above  the 
ganglion,  for  the  most  part  terminate  in  a gutter  formed  in  the  su- 
perior margin  of  the  ganglion,  and  that  there  are  but  very  few  of 
them  which  can  be  traced  into  the  trunks  below.  The  trunks  be- 
low, consequently,  arise  from  the  circumference  of  the  ganglion. 

The  two  smaller  roots  of  the  nervus  trigeminus  proceed  out  of 
the  tuber  annulare  at  different  points,  from  that  of  the  large  root, 
and  each  one  has  its  appropriate  fissure  for  that  purpose.  One, 
from  its  situation,  is,  as  stated,  called  Anterior,  and  the  other  Pos- 
terior. Each  may  be  traced  into  the  posterior  cord  of  the  medulla 
oblongata,  but  not  so  far  as  the  large  middle  root,  and  is  formed 
by  several  fasciculi  of  medullary  fibres.  The  anterior  and  posterior 
root,  after  going  separately  for  six  or  eight  lines,  unite  to  form  a 
single  cord.*  This  cord  does  not  merge  itself  in  the  semi-lunar 
ganglion,  but  continues  distinct  from  it, f with  the  exception  of 
sending  off  to  it  a few  fasciculi;  and  it  sometimes  has  its  own  dis- 
tinct canal,  and  aperture  in  the  dura  mater,  for  passing  through  it ; 
it  afterwards  gets  from  the  cranium  through  the  foramen  ovale,  and 
is  distributed  to  some  of  the  muscles  of  mastication,  as  the  temporal 
and  the  buccinator-; 

The  general  distribution  of  the  fifth  pair  of  nerves,  or  the  trige- 
minus, is  to  the  orbit,  to  the  face,  and  to  the  tongue. 

The  Motor  Externus  Oculi , (Sixth  Pair,  Par  Sextum ),  arises 

* These  two  constitute  what  is  called  the  motory  part  of  the  fifth  nerve.  Mr. 
Solly  considers  it  to  arise  from  the  valve  of  the  brain  near  its  root.  P.  249. 

t In  this  respect  the  fifth  pair  resembles  one  of  the  spinalnerves. 


408 


NERVOUS  SYSTEM. 


from  the  base  or  upper  extremity  of  the  corpus  pyra'midale,  under 
the  posterior  margin  of  the  tuber  annulare  or  Pons:  when  the 
latter  is  broader  than  usual,  sonye  of  the  fibres  seem  to  come  from 
it ; but  the  appearance  is  deceptious,  as  they  only  penetrate  it.  The 
fibres  are  assembled  into  two  roots,  of  which  the  internal  is  three 
or  four  times  as  large  as  the  other. 

These  roots  before  they  penetrate  the  dura  mater,  most  commonly 
unite  into  a single  trunk,  which  goes  almost  directly  forwards,  and 
is  enveloped  in  a neurileme.  Passing  through  the  cavernous  sinus, 
it  gets  into  the  orbit  by  the  sphenoidal  foramen,  and  is  spent  upon 
the  abductor  oculi  muscle. 

The  Seventh  Pair  of  Nerves  is  composed  of  the  Facial  and  the 
Auditory. 

The  Facial  Nerve  (, JYervus  Facialis , Portio  Dura  Septimi,  Par 
Septimum)  is  placed  in  front  of  and  above  the  auditory  nerve.  It 
arises  by  two  branches,  which  are  perfectly  distinct  from  each  other, 
and  differ  much  in  their  size.  The  larger  one,  which  is  placed 
within  and  above  the  other,  arises  from  the  medulla  oblongata  at  the 
most  superior  part  of  the  corpus  restiforme,  where  the  latter  joins 
the  tuber  annulare.  The  origin  of  the  nerve  is  sometimes  over- 
lapped by  the  latter,  so  that  some  few  of  its  fibres  appear  to  come 
from  the  annular  protuberance,  while  they  only  pass  through  it,  in 
their  course  from  the  medulla  oblongata.  The  second  branch, 
which  is  much  smaller  than  the  other  and  is  called  by  some  the  Pars 
Media  of  the  Seventh  Nerve,  arises  by  three  or  four  filaments,  from 
that  portion  of  the  medulla  oblongata  which  is  placed  between  the 
first  branch  and  the  auditory  nerve. 

The  two  branches  of  the  facial  nerve  are  kept  distinct  for  the  dis- 
tance of  several  lines  before  they  unite.  Proceeding  outwards  and 
backwards,  they  reach  the  meatus  auditorius  internus,  and  then  pro- 
ceed, as  a single  cylindrical  trunk,  through  the  aqueduct  of  Fallopius 
to  emerge  at  the  stylo-mastoid  foramen,  for  the  purpose  of  being 
distributed  upon  the  muscles  and  skin  of  the  head. 

The  Auditory  Nerve  (JYervus  Auditorius , Acusticus , Portio  Mollis 
Septimi)  arises,  in  part,  from  the  medullary  strirn  on  the  surface  of 
the  calamus  scriptorius,  and  partly  from  the  corpus  restiforme,  be- 
tween the  glosso-pharyngeal  nerve  and  the  tuber  annulare.  At  its 
origin  it  is  so  extremely  soft  as  not  to  bear  handling,  and  is  too 


NERVES  OF  THE  ENCEPHALON. 


409 


pulpy  to  present  the  appearance  of  fibres ; but,  becoming  more  dis- 
tant from  the  medulla  oblongata,  it  is  harder  and  more  fibrous. 

This  nerve  is  impressed  on  its  internal  face  by  a longitudinal  fur- 
row for  the  reception  of  the  facial  nerve.  It  passes  obliquely  for- 
wards and  outwards  beneath  the  crus  cerebelli,  and  penetrates  into 
the  meatus  auditorius  internus.  It  adheres  somewhat  near  its  root 
to  the  under  anterior  margin  of  the  cerebellum,  just  behind  the  crus 
of  the  latter : the  circumstance  is  considered  by  J.  F.  Meckel,  as  a 
proof  of  its  having  there  another  origin,  whereby  an  analogy  is  es- 
tablished between  it  and  the  two  other  nerves  of  the  senses ; to  wit, 
the  optic  and  the  olfactory. 

The  distribution  of  this  nerve  is  confined  to  the  labyrinth  of  the 
ear. 

The  Eighth  Pair  of  Nerves  is  composed  of  the  Glosso-Pharyngeal, 
the  Pneumogastric  and  the  Spinal  Accessory.* 

The  Glosso-Pharyngeal  Nerve  ( JYervus  Glosso-Pharyngeus,) 
arises  from  the  posterior  cord  of  the  medulla  oblongata,  just 
above,  and  somewhat  anterior  to  the  superior  filaments  of  the 
next  nerve,  with  which  it  is  very  closely  connected.  Its  fila- 
ments, which  are  five  or  six  in  number,  spring,  therefore,  from  the 
anterior  margin  of  the  corpus  restiforme,  or  from  the  fissure  sepa- 
rating it  from  the  corpus  olivare,  j under  the  posterior  margin  of  the 
tuber  annulare. 

Its  filaments  soon  collect  into  a round  cord,  and  anastomose, 
even  in  the  cavity  of  the  cranium,  by  a considerable  branch  with 
the  pneumogastric.  It  runs  outwards  and  backwards  to  the  foramen 
lacerum  posterius,  and  goes  through  the  same  division  of  it  that  the 
pneumogastric  does,  but  in  its  own  canal  of  the  dura  mater.  About 
half  an  inch  from  this  canal  it  enlarges  within  the  cranium,  into  a 
small  oblong  ganglion  of  five  or  six  lines  long,  which  extends  itself 
as  far  as  the  foramen  lacerum  4 

Its  general  distribution  is  to  the  tongue  and  to  the  pharynx,  as 
its  name  implies. 


* For  an  interesting’  course  of  experiments  on  the  eighth  pair,  by  John  Reid, 
M.  D.,  see  Essays  on  Physiology,  Phil.,  1838,  from  the  Edinburgh  Med.  and  Surgical 
Journal. 

t The  Corpus  Olivare  is  considered  by  Mr.  Solly  as  its  origin, 
t This  ganglion  is  described  by  Andersech  and  by  Huber,  but  its  existence  is 
questioned  by  Bichat. 


410 


NERVOUS  SYSTEM. 


The  Pneumogastric  Nerve  ( JYeivus  Pneumogastricus  or  Vagus') 
arises  from  the  corpus  restiforme  of  the  medulla  oblongata,  just 
behind,  or  on  the  borders  of  the  fissure  separating  it  from  the 
corpus  olivare,  somewhat  above,  and  posterior  to  the  highest 
root  of  the  accessory  nerve.  It  commences  by  a number  of  pa- 
rallel filaments,  varying  in  number  from  ten  to  fifteen,  which  are 
placed  very  near  each  other,  so  as  to  form  two  or  three  flattened 
fasciculi  of  half  an  inch  or  more  in  length.  The  fasciculi  below  ad- 
here to  the  spinal  accessory,  and  those  above  to  the  glosso-pharyn- 
geal  nerve.  The  fasciculi,  finally,  collect  into  a single  flattened  cord 
of  one  and  a half  lines  in  breadth. 

This  cord  goes  outwards  and  backwards  to  the  foramen  lacerum 
posterius,  and  gets  through  it  in  front  of  the  internal  jugular  vein, 
being  separated  from  the  latter  by  the  small  spine  which  arises 
from  the  pars  petrosa  of  the  temporal  bone.  It  passes  through  its 
own  canal  in  the  dura  mater,  being  thus  kept  distinct  from  the 
glosso- pharyngeal,  and  from  the  accessory  nerve,  and  in  this  canal 
the  fasciculi  which  form  it  are  collected  into  a single  cylindrical 
trunk.  After  getting  through  the  canal  it  then  adheres,  by  a close, 
strong,  cellular  substance,  to  the  glosso-pharyngeal  and  to  the  ac- 
cessory. 

The  general  plan  of  distribution  of  the  pneumogastric  nerve  is, 
as  its  name  implies,  to  the  organs  of  respiration,  and  to  the  sto- 
mach. 

The  Accessory  Nerve,  ( JVervus  Accessorius ,)  arises  from  the 
posterior  fasciculus  of  the  medulla  oblongata,  behind  the  nervus 
hypoglossus,  and  also  from  the  posterior  fasciculus  of  the  me- 
dulla spinalis,  sometimes  as  low  down  as  the  seventh  cervical 
nerve.  There  are  six  or  seven  roots  from  the  medulla  spinalis,  and 
about  three  or  four  from  the  medulla  oblongata:  the  former  are  sin- 
gle, and  run  successively  into  the  same  trunk ; but  the  latter  are 
each  composed  of  two  branches,  consisting  respectively  of  two  or 
more  filaments.  These  roots  are,  successively  larger  and  longer, 
as  they  ascend  to  join  the  common  trunk.  The  latter  goes  up  be- 
tween the  posterior  fasciculi  of  spinal  nerves  and  the  ligamentum 
denticulatum,  and  gets  into  the  cavity  of  the  cranium,  behind  the 
vertebral  artery,  through  the  foramen  magnum  occipitis.  It  is  joined 
sometimes  by  a sort  of  knot  to  the  posterior  fasciculi,  or  root  of  the 
first  and  second  cervical  nerves ; this  knot  seems  to  be  neither  after 


ARTERIES  OF  THE  BRAIN. 


411 


the  fashion  of  ganglion  or  plexus,  but  is  peculiar,  and  looks  some- 
what as  if  one  nerve  were  wrapped  around  the  other. 

This  nerve  varies  in  respect  to  the  number  of  its  roots,  and  the 
mode  of  their  origin.  In  all  cases,  the  trunk,  thus  formed,  passes 
from  the  cranium  through  the  foramen  lacerum  posterius,  traversing 
there  the  dura  mater,  either  in  a sheath  common  to  it  and  to  the 
pneumo-gastric  nerve,  or  in  its  own  particular  opening  behind  that 
of  the  latter. 

Its  general  distribution  is  to  the  muscles  and  to  the  integuments 
of  the  neck. 

The  Hypoglossal  Nerve,  (Ninth  Pair,  ( JVervus  Hypoglossus ,) 
arises  from  the  medulla  oblongata,  by  several  fasciculi  placed  one 
above  the  other.  The  roots  of  these  fasciculi  spring  from  the  fissure 
which  separates  the  corpus  pyramidale  from  the  corpus  olivare, 
being  traced  to  that  surface  of  the  corpus  pyramidale.  The  fasciculi 
are  from  four  to  eight  in  number,  being  subject  to  vary  in  different 
individuals.  They  unite  into  two  or  three  trunks,  which  coalesce 
into  one,  after  penetrating  the  dura  mater  by  distinct  openings  ; and 
then  proceed  through  the  anterior  condyloid  foramen  of  the  occipital 
bone. 

Santorini  has  observed  in  some  cases  a posterior  root  to  the  Hy- 
poglossal nerve,  and  in  one  instance  where  the  same  was  found  by 
Mayer  it  had  a ganglion. 

The  general  distribution  of  this  nerve  is  to  the  muscles  of  the 
tongue. 


SECT.  VII. — OF  THE  ARTERIES  OF  THE  BRAIN.* 

The  arteries  of  the  brain,  or  pia  mater,  are  derived  from  the  two 
internal  carotids,  and  from  the  two  vertebrals. 

The  Internal  Carotid  Artery  ( Carotis  Interna ) gets  into  the  cavity 
of  the  cranium  through  the  Carotid  canal  of  the  temporal  bone,  con- 
forming itself  of  course  to  the  curvature  of  this  canal,  and  is  brought 
by  it  to  the  posterior  part  of  the  body  of  the  sphenoidal  bone.  In 

* Anat.  Atlas,  Fig.  548j 


412 


NERVOUS  SYSTEM. 


escaping  from  the  petrous  bone  it  has  to  ascend,  and  also  to  advance 
somewhat,  by  which  it  is  brought  to  the  posterior  part  of  the  sella 
turcica.  From  this  point  it  goes  horizontally  forwards  through  the 
cavernous  sinus;  and,  reaching  its  fore  part,  it  then  ascends  again, 
and  towards  the  fissure  of  Sylvius.  While  in  the  carotid  canal,  it 
gives  a small  branch  to  the  tympanum  of  the  ear,  and  as  it  lies  on 
the  side  of  the  sella  turcica  it  gives  off'  the  anterior  and  the  posterior 
artery  of  the  cavernous  sinus.  When  it  reaches  the  anterior  clinoid 
process  it  sends  off  a large  branch,  through  the  optic  foramen,  to  the 
parts  contained  within  the  orbit  of  the  eye.  This  branch  is  the  oph- 
thalmic artery,  and  what  remains  of  the  internal  cartoid  is  then  dis- 
tributed to  the  brain  after  the  following  order: 

There  are,  first  of  all,  some  small  branches  sent  to  the  adjacent 
parts ; as  the  pituitary  gland,  the  infundibulum,  and  the  lower  part 
of  tire  third  ventricle. 

The  Arteria  Communicans  Posterior  is  directed  backwards  and 
inwards,  and  runs  into  the  adjacent  branch  of  the  basilar  artery, 
called  the  posterior  cerebral.  There  are  some  varieties  in  regard  to 
the  size  and  precise  point  of  origin  of  the  communicans  posterior 
which  it  would  be  needless  to  mention  particularly.  Besides  this 
important  anastomosis,  the  internal  carotid  detaches  several  ramus- 
cles  to  the  adjacent  parts  of  the  pia  mater. 

The  Arteria  Choroidea  is  the  next  branch  from  the  internal  carotid. 
It  goes  outwards  and  backwards,  and  after  detaching  some  minor 
branches,  it  penetrates  into  the  inferior  cornu  of  the  lateral  ventricle, 
by  the  side  of  the  Pons  Varolii,  and  expends  itself  in  ramifications 
upon  the  plexus  choroides. 

The  Arteria  Callosa,  or  Anterior  Cerebri,  is  detached  from  the 
internal  carotid,  opposite  the  last.  It  advances  in  front  of  the  union 
of  the  optic  nerves,  converging  rapidly  at  the  same  time  towards  its 
fellow.  Just  before  the  chiasm  of  the  optic  nerves,  a transverse 
branch  passes  between  it  and  its  fellow.  This  branch,  the  Arteria 
Communicans  Anterior,  is  of  variable  length  and  size  in  different 
subjects,  being  sometimes  a line,  and  on  other  occasions  three  or 
four  lines  long.  Sometimes  there  are  two  arteries,  one  before  the 
other. 

The  arteria  callosa  then  keeps  near  its  fellow  on  the  under  sur- 
face of  the  hemisphere,  giving  out  small  branches  ; and  having  got 


ARTERIES  OF  THE  BRAIN. 


413 


on  a line  with  the  anterior  margin  of  the  corpus  callosum,  it  ascends 
on  the  flat  side  of  the  hemisphere,  and  divides  into  anterior  and  into 
posterior  twigs.  The  former  supply  the  fore  flat  part  of  the  hemi- 
sphere ; the  latter,  the  corpus  callosum  and  the  adjacent  surface  of 
the  brain.  These  several  branches  of  the  arteria  anterior,  reach  as 
far  as  the  upper  convex  surface  of  the  brain,  and  there  anastomose 
with  other  arteries. 

The  Internal  Carotid  may  now  be  considered  to  have  lost  its  name, 
and  the  trunk  is  continued  as  Arteria  Media  Cerebri.  It  is  directed 
outwards,  and  engages  in  the  fissure  of  Sylvius;  while  there  it  de- 
taches a great  number  of  branches  to  the  adjoining  surfaces  of  the 
anterior  and  of  the  middle  lobe.  Some  of  these  branches  are  of 
considerable  magnitude,  and  winding  along  the  convolutions  of  the 
brain,  they  at  length  ascend  to  the  upper  surface  of  the  hemisphere, 
and  anastomose  with  the  branches  of  the  anterior  and  of  the  posterior 
cerebral  artery. 

The  Vertebral  Artery  {Arteria  Vertebralis ) is  a branch  of  the  sub- 
clavian. In  order  to  reach  the  cavity  of  the  cranium  it  has  to  tra- 
verse the  foramina  of  the  transverse  processes  of  the  six  upper  verte- 
brae of  the  neck.  It  ascends  in  a straight  line  till  it  reaches  the 
second  vertebra,  but  there,  in  order  to  pass  through  the  transverse 
process,  it  takes  a direction  upwards  and  outwards.  It  then  ascends 
vertically  again  till  it  has  passed  through  the  transverse  process  of 
the  first  vertebra.  After  which  it  takes  a horizontal  course,  winding 
around  the  posterior  face  of  the  upper  oblique  process  of  the  same 
vertebra,  in  a depression  for  the  purpose  ; and  having  reached  the 
internal  extremity  of  this  process,  it  ascends  upwards  and  inwards 
through  the  occipital  foramen  into  the  cavity  of  the  cranium,  perfora- 
ting the  dura  mater  just  above  the  condyle  of  the  occipital  bone. 
Having  got  into  the  cranium,  it  is  first  on  the  side  and  then  on  the 
under  surface  of  the  medulla  oblongata,  and  continues  to  approach 
its  fellow  till  it  reaches  the  posterior  margin  of  the  tuber  annulare. 
At  this  point  the  two  vertebral  arteries  coalesce,  and  from  their  union 
results  the  basilar  artery. 

The  vertebral  artery  in  this  course,  from  its  origin  to  its  termi- 
nation, detaches  several  arterioles  to  the  heads  of  the  adjoining 
muscles,  to  the  membranes  of  the  spinal  marrow,  and  to  the  nerves 
as  they  come  out  of  the  intervertebral  foramina:  they  are  generally 
too  small  and  irregular  to  deserve  a special  description.  At  its 
Vol.  II. — 36 


414 


NERVOUS  SYSTEM. 


upper  extremity,  however,  it  sends  off  three  branches  of  some  con- 
sequence: the  Spinalis  Posterior,  the  Spinalis  Anterior,*  and  the 
Inferior  Cerebelli. 

The  Arteria  Inferior  Cerebelli  divides  shortly  after  its  origin,  or 
otherwise  is  double  from  the  beginning.  The  most  posterior  trunk 
is  distributed  about  the  bottom  of  the  fourth  ventricle,  on  the  fun- 
damental portion  of  the  cerebellum,  and  the  contiguous  faces  of 
the  two  hemispheres  or  lobes  of  the  latter.  The  other  trunk  of  this 
artery  is  distributed  on  the  under  surface  of  the  cerebellum. 

The  Basilar  Artery  ( Arteria  Basilaris ) is  on  the  middle  line  of 
the  tuber  annulare,  and  extends  from  its  posterior  to  its  anterior 
margin.  In  this  course  it  detaches  some  arterioles  to  the  tuber ; 
others  to  the  meatus  auditorius  internus,  ( Arteries  Auditivce  Internee ,) 
which  are  spent  upon  the  labyrinth,  and  anastomose  with  twigs  from 
tlie  internal  and  external  carotids.  At  its  anterior  extremity  it  de- 
taches on  each  side  two  considerable  trunks  ; first  the  superior  artery 
of  the  cerebellum,  and  immediately  afterwards  the  posterior  artery 
of  the  cerebrum. 

The  Arteria  Superior  Cerebelli  goes  outwardly  from  its  origin  just 
behind  the  anterior  edge  of  the  tuber  annulare,  until  it  gains  the  front 
margin  of  the  cerebellum.  It  then  divides  into  several  branches, 
some  of  which  are  distributed  on  the  upper  surface  of  the  cerebellum 
•and  run  to  its  posterior  margin,  where  they  anastomose  with  the 
branches  of  the  arteria  inferior : others  are  spent  upon  the  substance 
of  the  cerebellum  near  its  anterior  edge. 

The  Posterior  Artery  of  the  Cerebrum,  [Arteria  Cerebri  Posterior ,) 
one  on  each  side,  is  the  termination  of  the  basilar  artery.  It  pro- 
ceeds abruptly  outwards,  and  has  gone  but  a few  lines  when  it  re- 
ceives the  arteria  communicans  posterior  of  the  internal  carotid.  It 
then  continues  outwardly  parallel  with  the  anterior  margin  of  the 
tuber  annulare,  and  near  it  crosses  the  crus  cerebri,  and  is  then  dis- 
tributed, on  the  inferior  and  on  the  posterior  part  of  the  hemisphere 
and  of  the  corpus  callosum.  As  mentioned,  its  branches  anastomose 
with  those  of  the  anterior  and  of  the  middle  artery  of  the  cerebrum. 

It  will  nowT  be  understood,  that  an  arterial  circle  or  link  encloses 
the  chiasm  of  the  optic  nerves  and  the  corpora  albicantia.  The 


* See  Arteries  of  Medulla  Spinalis, 


ARTERIES  OF  THE  BRAIN. 


415 


fore  and  lateral  parts  of  the  circle  are  formed  by  the  internal  caro- 
tids and  their  branches  ; while  the  hind  part  is  formed  by  the  Ba- 
silar Artery  and  its  bifurcation.  This  is  the  circle  of  Willis,  and 
establishes  a very  free  communication  between  the  vessels  of  the 
two  sides  of  the  brain. 


The  veins  of  the  Brain  have  been  sufficiently  alluded  to  in  the 
account  of  the  Pia  Mater,  and  of  the  sinuses  of  the  Dura  Mater, 


s 


I 


I 


BOOK  IX* 


FART  III* 

SENSES. 

To  the  peripheral  portion  of  the  nervous  system,  belong  all  the 
nerves  which  are  sent  off  from  the  Medulla  Spinalis  and  Encepha- 
lon, and  also  the  Sympathetic.  Some  of  these  nerves  have  a special 
apparatus  attached  to  their  external  extremities,  for  the  purpose  of 
augmenting  and  facilitating  their  appropriate  powers  of  sensation  ; of 
this  class  are  the  Olfactory,  the  Optic,  and  the  Auditory.  Others  of 
them,  as  the  nerves  of  the  tongue  and  of  the  skin,  though  they  are  the 
means  of  special  sensation,  yet  the  apparatus  upon  which  they  are 
spread  is  applied  to  many  purposes,  more  striking  and  useful,  than 
that  of  indicating  the  presence  of  surrounding  bodies.  And,  lastly, 
the  remaining  nerves,  being  by  far  the  most  numerous  and  large,  are 
distributed  to  the  muscles  and  to  the  viscera. 


CHAPTER  I. 

Of  the  Organ  of  Smelling,  or  the  Nose.* 

The  senses  of  Vision  and  Hearing  are  so  insulated  in  their  offices? 
that  there  can  be  no  doubt  of  the  propriety  of  considering  them  as 
belonging  to  the  peripheral  portion  of  the  nervous  system  : but  the 
nose  being  in  the  human  subject,  though  not  in  all  animals,  attached 


* Anat,  Atlas.  Figs.  549  to  557,  inclusive. 

36* 


418 


NERVOUS  SYSTEM. 


to  the  function  of  respiration,  its  association  here  is  less  admissible. 
Without  detailing  the  considerations  which  have  induced  me  to  put 
its  description  under  this  head,  I will  only  mention  that  I have  been 
principally  actuated  by  its  office  of  smelling  and  by  its  position. 

In  common  language,  the  term  nose  is  applied  to  the  part  of  the 
oigan  of  smelling  which  manifests  itself  externally ; but  a very  ex- 
tensive cavity  of  the  same  vertical  diameter,  and  divided  into  two 
equal  compartments,  exists  behind  it,  the  form  of  which  has  been 
described  in  the  account  of  the  bones  of  the  nose.  This  cavity  ex- 
tends from  the  bottom  of  the  cranium  to  the  roof  of  the  mouth,  and 
backwards  to  within  an  inch  and  a quarter  of  the  vertebrae  of  the 
neck.  The  nose,  externally,  is  generally  pyramidal,  and  has  its 
base  below ; what  is  technically  called  the  root  of  the  nose  is  the 
part  contiguous  to  the  forehead.  The  base,  on  each  side,  is  marked 
from  the  cheek  by  a semi-circular  depression  ; which  becoming  more 
and  more  shallow  at  its  upper  extremity,  and  increasing  in  breadth, 
is  insensibly  lost  upon  the  side  and  point  of  the  nose.  The  ala  nasi 
is  the  swell  of  the  posterior  part  of  the  base,  being  bounded  behind 
by  the  above  depression.  The  base  of  the  nose  offers  on  each  side 
an  oblong  oval  orifice,  looking  downwards  and  having  its  long  dia- 
meter forwards  and  slightly  inwards.  These  openings  are  com- 
monly about  two  lines  below  the  floor  of  the  nose,  but  there  is  a 
diversity  in  this  respect. 

The  Nasus  Cartilagineus,  or  the  cartilaginous  portion  of  the  nose 
is  placed  wholly  at  its  anterior  extremity,  and  serves  to  elongate  the 
cavity  in  that  direction.  It  presents  a vertical  cartilage,  which  is  in 
continuation  of  the  bony  septum  : on  each  side  of  this,  there  is  an 
oval  cartilage,  and  behind  and  below  the  latter,  several  distinct  and 
small  pieces  of  cartilage,  which  preserve  the  form  of  the  aim  nasi, 
and  constitute  their  foundation. 

The  Vertical  Cartilage,  or  Cartilaginous  Septum  ( Septum  Carti- 
lagineum ,)  is  placed  on  the  middle  line  of  the  nose,  and  has  its  an- 
terior angle  projecting  beyond  the  bony  orifice  of  the  anterior  nares. 
Occasionally  from  a faulty  conformation,  it  inclines  more  to  one 
side  than  to  the  other.  It  adheres  by  its  superior  margin,  to  the 
nasal  lamella  of  the  ethmoid  and  to  the  middle  nasal  suture,  and  be- 
hind to  the  anterior  margin  of  the  vomer.  The  inferior  margin  is 
free  in  the  greater  part  of  its  extent,  but  adheres  behind  to  the  suture 
between  the  maxillary  bones.  The  anterior  margin  sends  out,  on 


ORGAN  OF  SMELLING. 


419 


each,  side,  a triangular  plate,  the  upper  edge  of  which  adheres  to  the 
inferior  margin  of  the  nasal  bone,  and  of  the  nasal  process  of  the 
upper  maxillary.  These  plates  form  the  upper  part  of  the  cartilagi- 
nous nose,  and  from  their  ligamentous  attachment  to  the  bones,  admit 
of  a slight  motion  from  side  to  side. 

Huschke  has  described*  a distinct  cartilage  at  each  side  of  the 
cartilaginous  septum  below,  which  may  be  found  separate  by  macera- 
tion, he  calls  them  the  Vomerian  cartilages.  They  are  about  half  an 
inch  in  length,  and  the  point  of  the  Vomer  is  insinuated  between 
them. 

The  Oval  Cartilages,  one  on  each  side,  are  a sort  of  semi-elliptical 
ring,  deficient  or  open  at  their  posterior  end.  The  external  side  of  the 
ring,  is  an  oblong  oval  plate,  which  is  directed  upwards  and  back- 
wards. The  internal  half  of  the  ring  is  much  narrower,  and  pro- 
ceeds backwards  from  the  preceding  part  at  a very  acute  angle  : its 
superior  margin  is  in  contact  with  the  septum  cartilagineum ; its  in- 
ferior margin  reaches  below  the  latter,  and  its  anterior  extremity  is 
in  contact  with  its  fellow,  owing  to  the  cartilaginous  septum  not 
reaching  so  far  forwards.  The  place  of  contact  of  the  two  oval  car- 
tilages with  each  other,  forms  the  tip  of  the  nose  and  the  Columna 
Nasi,  and  gives  the  apparent  thickness,  before  dissection,  to  the 
lower  part  of  the  septum  narium. 

The  Alas  Nasi,  or  the  convexities  on  each  side  of  the  base  of  the 
nose,  it  has  been  said  owe  their  shape  to  the  presence  of  several 
small  pieces  of  cartilage,  whose  form,  size,  and  number  are  too 
variable  to  admit  of  a standard  description : occasionally  they  are 
all  collected  into  but  one  cartilage.  They  serve  a similar  purpose 
with  the  oval  cartilage,  and  with  it  are  the  means  by  which  the  ori- 
fice of  the  nostril  is  kept  patulous.  They  are  deposited  in,  and 
held  together  by  a ligamentous  membrane.  This  membrane  at- 
taches them  to  the  lateral  margin  of  the  anterior  bony  naris,  and 
also  unites  the  upper  edge  of  the  external  plate  of  the  oval  cartilage 
to  the  inferior  margin  of  the  triangular  plate  of  the  cartilaginous 
septum.  It  is  the  length  and  looseness  of  this  ligament  which  per- 
mit such  free  motion  to  the  end  of  the  nose.  In  addition  there  ex- 
ists a small  ligament  described  by  Caldani,  which  goes  from  the 
posterior  end  of  the  columna  nasi  to  the  anterior  inferior  margin  of 
the  bony  nares. 


* Loc.  cit.  p.  5S7. 


420 


NERVOUS  SYSTEM. 


The  skin  which  covers  the  upper  half  of  the  nose  is  loosely  at- 
tached, by  cellular  substance,  to  the  subjacent  parts,  but  it  adheres 
very  closely  by  fibrous  filaments  to  the  surface  of  the  cartilaginous 
and  ligamentous  structure,  and  is  abundantly  furnished  Avith  seba- 
ceous follicles.  The  exterior  orifices  of  the  latter  are  apparent,  and 
are  often  filled  with  their  appropriate  fluid  in  an  inspissated  state, 
and  which,  when  forced  out  by  pressure,  assumes  the  form  of  small 
worms,  the  blackness  of  the  end  of  which  is  only  dirt. 

There  are  several  muscles  destined  to  move  the  cartilaginous 
structure  of  the  nose,  and  which  have  been  described  among  those 
belonging  to  the  face.  They  are, 

The  Levator  Labii  Superioris  Alceque  Nasi  which  lies  upon  the 
side  of  the  nose  and  coming  from  the  superior  part  of  the  nasal  pro- 
cess and  body  of  the  upper  maxillary  bone,  is,  besides  its  insertion 
into  the  upper  lip,  connected  with  the  ala  nasi,  and  will  draw  the 
latter  upwards : — 

The  Compressor  Naris,  which  arising  from  the  ala  nasi  by  a small 
pointed  beginning,  is  spread  out  upon  the  upper  edge  of  the  oval 
cartilage  and  upon  the  triangular  plate  of  the  cartilaginous  septum, 
so  as  to  cover  them,  and  is  inserted  into  its  felloAV  on  the  middle 
line : — 

The  Depressor  Labii  Superioris  Alceque  Nasi,  AAThich  by  arising 
from  the  roots  of  the  alveolar  processes  of  the  incisor  and  canine 
teeth  of  the  upper  jaw,  and  going  to  be  inserted  into  the  ala  nasi,  as 
well  as  into  the  upper  lip,  will  draw  the  ala  nasi  doAvnwards : — 

And  the  Nasalis  Labii  Superioris,  or  Depressor  Narium,  Avhich 
being  the  pointed  production  from  the  orbicularis  oris,  goes  into 
the  columna  nasi,  and  will  draw  the  latter  downwards  and  back- 
wards. 

The  Mucous  Membrane  of  the  Nose  ( Membrann  Pituitaria, 
Sclineideriana ) lines  the  Avhole  of  each  side  of  the  nose,  penetrates 
into  the  several  sinuses  and  cavities  communicating  with  it,  and  is 
continuous,  at  the  orifice  of  the  Nostrils,  with  the  skin,  and  at  the 
posterior  nares,  Avith  the  mucous  membrane  of  the  pharynx. 

It  is  not  of  essential  importance  to  trace  its  course  from  any  par- 
ticular point,  but  for  the  sake  of  perspicuity,  Ave  may  begin  at  the 
floor  of  the  nostril  Avhich  it  covers  in  a smooth  even  manner,  some- 
times leaAring  a small  opening  into  the  mouth,  by  the  foramen  inci- 
sivum.  This  opening  is  called  the  duct  of  Stenson,  an  anatomist 


ORGAN  OF  SMELLING. 


421 


of  the  seventeenth  century,  who  discovered  it.  From  below  it  as- 
cends on  the  septum  narium,  which  it  covers  also  smoothly  without 
forming  any  fold  or  duplicature,  and  adheres  so  loosely  that  it  may 
be  detached  with  great  facility.  Behind,  it  covers  the  body  of  the 
sphenoid  bone,  and  lines  its  cell;  in  front,  it  covers  smoothly  the  os 
nasi  and  nasal  process  of  the  upper  maxillary  bone,  and  also  the  car- 
tilaginous nose.  Above,  it  is  reflected  upon  the  cribriform  plate  of 
the  ethmoid  bone,  and  blocks  up  all  its  foramina.  At  this  point, 
the  olfactory  nerves  seem  to  terminate  on  its  surface  and  adhere  very 
closely  to  it. 

From  the  cribriform  plate,  the  Schneiderian  membrane  passes  to 
the  cellular  part  of  the  ethmoid,  and  covers  smoothly  its  anterior 
half.  But  behind,  as  it  passes  over  the  upper  spongy  bone,  a pen- 
dulous duplicature  is  formed  along  its  inferior  margin,  and  is  con- 
tinued beyond  the  bone,  backwards  as  far  as  the  spheno-palatine 
foramen.  It  then  lines  the  upper  meatus  and  the  posterior  cells  of 
the  ethmoid,  and  is  extended  upon  the  convex  surface  of  the  middle 
spongy  bone.  At  the  inferior  margin  of  the  latter,  it  forms  another 
loose  and  somewhat  pendulous  duplication,  which  does  not  go  much 
beyond  the  posterior  extremity  of  the  bone.  The  membrane  is  then 
reflected  into  the  middle  meatus  of  the  nose,  and  penetrates  into  the 
maxillary  sinus  which  it  lines  completely.  The  orifice  through  which 
it  enters,  is  about  the  size  of  a crow-quill ; is  variable  in  its  situation, 
being  sometimes  in  the  middle  of  the  meatus,  sometimes  more  for- 
ward, and  on  other  occasions  higher  up  and  concealed  by  irregu- 
larities, in  the  conformation  of  the  ethmoid.  This  orifice,  which 
was  found  to  be  so  large  and  jagged  in  the  prepared  bone,  is  re- 
duced to  its  present  size  entirely  by  the  mode  of  reflection  of  the 
mucous  membrane  over  its  margins.  In  front  of  the  latter  orifice, 
beneath  the  anterior  margin  of  the  middle  turbinated  bone,  the  mu- 
cous membrane  is  reflected  into  the  anterior  ethmoidal  cells  by  one 
or  more  foramina,  and  through  the  most  anterior  of  these  cells  into 
the  frontal  sinus. 

From  the  middle  meatus,  this  membrane  passes  upon  the  lower 
turbinated  bone  so  as  to  cover  it,  and  also  to  form  a loose  duplica- 
tion along  its  inferior  margin  ; it  then  lines  the  inferior  meatus  of  the 
nose,  and  is  continued  on  its  floor  into  the  part  from  which  its  de- 
scription commenced.  Under  the  anterior  part  of  the  inferior  spongy 
hone,  this  membrane  is  continued  into  the  lining  membrane  of  the 
lachrymal  sac,  and  there  forms  a fold  frequently  resembling  a valve. 


422 


NERVOUS  SYSTEM. 


Along  the  posterior  margin  of  the  vomer,  the  membrane  of  the  nostril 
Js  continued  into  the  corresponding  one  of  the  other  side,  whose  ar- 
rangement is  in  all  respects  the  same. 

The  pituitary  membrane,  in  its  structure  and  appearance,  resem- 
bles other  mucous  membranes  ; its  colour,  however,  is  naturally  of  a 
deeper  red.  ft  consists  of  two  laminee,  which  cannot  be  readily 
separated : the  one  next  to  the  cavity  of  the  nostril  has  the  mucous 
structure ; the  exterior  one  is  fibrous,  and  resembles  the  periosteum 
of  other  parts  of  the  body.  This  composition  is  best  seen  on  the 
part  belonging  to  the  septum  narium. 

By  floating  the  pituitary  membrane  in  water  its  mucous  lamina 
is  made  to  exhibit,  very  satisfactorily,  the  villous  and  spongy  ap- 
pearance. This  is  particularly  evident  on  the  turbinated  bones.  Its 
whole  surface  is  studded  with  pits  or  follicles  of  various  sizes,  irre- 
gularly arranged  and  resembling  pricks  made  into  a plastic  substance 
with  the  point  of  a pin.  From  these  cavities  or  cryptse  proceeds  the 
mucus  of  the  nose.  In  the  thickness  of  the  pituitary  membrane,, 
there  exist  numerous  and  thickly  set  glands,  of  a size  so  small  that 
they  escape  common  observation,  but  their  existence  is  generally 
admitted,  both  on  the  authority  of  anatomists  who  have  described 
them,*  and  on  the  principle  of  their  being  always  the  concomitants 
of  mucous  membranes. f 

These  glands,  according  to  Valentin,  in  some  parts  of  the  nose 
consist  of  contorted  tubes,  resembling  somewhat  microscopic  intes- 
tines ; and  which  are  surrounded  and  separated  by  circular  filaments 
of  cellular  substance.  The  glands  are  especially  well  developed  at 
the  posterior  and  inferior  part  of  the  septum  narium. 

It  is  owing  to  the  great  abundance  of  blood  vessels  in  this  mem- 
brane, to  their  very  superficial  course,  and  to  the  habitual  residence 
of  blood  in  them,  that  it  always  presents  a deep  red  colour  in  the 
living  state.  These  blood  vessels  bleed  very  freely  from  slight  me- 
chanical causes,  and  are  also  disposed  to  congestions,  which  are- 
relieved  by  the  blood  being  poured  out  through  their  exhalant  ori- 
fices, without  laceration  or  any  solution  of  continuity. 

Though  the  description  just  given  corresponds  with  the  texture, 
generally,  of  the  pituitary  membrane,  yet  there  are  modifications  of 
the  latter  at  particular  points  which  it  does  not  fully  suit.  For  ex- 
ample, at  the  anterior  orifice  of  the  nostril  it  is  insensibly  changed 


Ruyschii,  Epist.  Anat.  Probl.  vii.  Mayer. 


t Bichat,  Anat.  Deecrip^ 


ORGAN  OF  SMELLING. 


423 


into  a thin  skin,  famished  in  the  male  adult  with  stiff  hairs  ( Vibrissa  ;) 
and  in  all  the  sinuses  it  is  more  thin  and  white  than  elsewhere,  being 
also  smooth  and  shining,  and  not  presenting  clearly  the  little  pits 
which  are  so  distinct  in  the  nose.  The  surface  which  adheres  to  the 
sides  of  the  sinuses,  is  destitute  of  a fibrous  structure,  and  resembles 
condensed  but  very  thin  cellular  membrane,  and  is  so  loosely  attached 
that  it  peels  off  with  a very  inconsiderable  force.  When  the  mem- 
brane of  the  sinuses  is  inflamed,  it  then  thickens,  admits  more  red 
blood,  and  is  thus  brought  to  resemble  the  pituitary  elsewhere. 

It  is  extremely  difficult  to  assign  a proper  use  to  the  sinuses  bor- 
dering on  and  entering  into  the  nose  ; for,  according  to  Dessault,  the 
sensation  of  smell  does  not  exist  in  them.  Bichat  believed  that  they, 
by  being  filled  with  air  charged  with  odorous  particles,  were  reser- 
voirs of  the  latter,  serving  to  prolong  the  sensation  of  smell,  which 
would  have  been  too  fugitive  if  it  had  depended  only  on  the  passage 
of  air  during  respiration.  Another  problem  in  regard  to  these  cavi- 
ties, is  the  manner  in  which  they  discharge  the  mucus  which  they 
secrete.  Perfectly  rigid  and  unyielding,  and  so  situated  that  the 
most  frequent  attitudes  of  the  head  wrould  rather  serve  to  retain,  than 
to  discharge  the  contents  of  most  of  them  by  gravitation,  we  yet 
seldom  see  their  surface  more  than  smeared  with  mucus,  and  accu- 
mulations of  it  are  quite  uncommon,  except  in  the  diseased  state. 
The  secretion  in  them,  it  is  to  be  observed,  is  much  less  abundant 
than  it  is  in  the  nose. 

Of  the  Nerves  of  the  Pitwitary  Membrane* 

The  pituitary  membrane  is  furnished  with  nervesf  from  two 
sources  ; from  the  olfactory,  and  from  the  fifth  pair. 

The  Olfactory  Nerve  having  formed  its  bulb,  which  reposes  in 
the  ethmoidal  fossa,  sends  off  from  the  under  surface  of  the  bulb, 
the  succession  of  filaments  which  penetrate  to  the  nose  through  the 
cribriform  plate  of  the  ethmoidal  bone.  The  latter,  when  examined 
from  the  upper  surface,  has  its  foramina  arranged  into  two  rows,  one 
next  to  the  crista  gall i , and  the  other  next  to  the  cellular  portion  of 
the  ethmoid.  Each  row  consists  of  about  six  or  eight  foramina,  and 
between  these  row's  there  are  other  foramina,  smaller,  and  not  so 


* Anton ii  Scarpa,  Anatom.  Annotationes,  Lib.  ii. 
t Anat.  Allas,  Fig.  616. 


424 


NERVOUS  SYSTEM. 


much  in  a line  with  each  other.  The  same  cribriform  foramina? 
when  examined  from  the  cavity  of  the  nose,  are  more  numerous,  es- 
pecially those  belonging  to  the  first  two  rows,  in  consequence  of 
the  latter  branching  out  below  into  several  canals,  which  may  be  seen 
very  distinctly  on  the  side  of  the  base  of  the  nasal  lamella,  and  on 
that  of  the  cellular  portion  of  the  ethmoid. 

The  distribution  of  the  olfactory  nerve  corresponds  with  this  ar- 
rangement of  the  cribriform  plate ; for  it  has  three  rows  of  branches 
proceeding  from  the  under  surface  of  its  bulb,  each  branch  going 
through  its  appropriate  foramen,  and  subdividing  in  it ; but  sometimes 
two  filaments  pass  through  the  same  foramen.  In  a short  space  after 
their  origin,  they  become  invested  by  sheaths  of  the  dura  mater, 
which  are  extended  a considerable  distance,  and  which,  by  a close 
adhesion  to  the  nerves,  make  them  appear  much  larger  below  than 
they  are  at  the  roots.  When  the  nerves  reach  the  cavity  of  the  nose 
they  anastomose  together,  and  descending  between  the  bone  and  the 
pituitary  membrane,  they  ramify  into  an  infinitude  of  small  branches, 
the  terminating  filaments  of  which  reach  the  nasal  surface  of  the 
membrane. 

The  Internal  Branches,  or  those  next  to  the  crista  galli,  diverge 
from  the  cribriform  plate,  and  pass  downward  between  the  septum 
and  the  pituitary  membrane:  where  they  first  appear  in  the  nose, 
there  are  some  few  adhesions  or  anastomoses  between  them  ; but 
their  filaments  afterwards  keep  perfectly  distinct,  and,  spreading 
themselves  out  on  the  pituitary  membrane  of  the  septum,  make  an 
appearance  resembling  a flat  camel’s  hair  pencil.  The  middle  ones 
are  the  longest,  and  may  be  traced  almost  to  the  floor  of  the  nose ; 
the  anterior  are  shorter  somewhat ; the  posterior  do  not  reach  ob- 
viously below  the  middle  of  the  septum. 

The  External  Branches  have  a very  different  mode  of  distribu- 
tion. While  still  in  their  canals  they  divide  into  many  filaments, 
which  anastomose  frequently  with  each  other,  and  when  they  have 
fairly  got  into  the  cavity  of  the  nose,  the  same  frequency  of  anasto- 
mosis continues,  so  that  they  form  a net-work  of  numerous  and  small 
meshes,  which  prevails  from  the  cribriform  plate  to  the  inferior 
margin  of  the  middle  turbinated  bone.  Their  filaments  cannot  be 
traced  below  the  latter  line,  and  therefore,  do  not  descend  so  low  as 
the  filaments  of  the  internal  row,  neither  are  they  so  close  to  each 
other.  They  do  not  penetrate  to  the  ethmoidal  cells.  The  posterior 
ones  are  very  abundant,  on  the  upper  turbinated  bone,  and  incline 


ORGAN  OF  SMELLING. 


425 


backwards  in  their  descent;  the  anterior  are  also  abundant  on  the 
flat  anterior  half  of  the  ethmoid,  and  when  they  get  below  the  line  of 
the  upper  meatus,  they  extend  backwards  to  the  posterior  end  of  the 
middle  turbinated  bone,  and  to  its  inferior  margin.  On  this  bone 
they  are  less  abundant  than  above  it ; their  meshes  are  larger,  and 
their  distribution  its  confined  to  the  Schneiderian  membrane  covering 
its  convex  surface. 

The  filaments  of  the  Middle  row  from  the  Bulb  of  the  Olfactory 
nerve,  associate  themselves  indiscriminately  with  those  of  the  external 
and  of  the  internal  row,  according  to  local  convenience. 

The  other  nerves  of  the  Pituitary  Membrane  come  from  the  first, 
and  from  the  second  branch  of  the  Trigeminus.  The  first  branch 
of  the  latter  gives  off  from  its  nasal  branch  the  nerve  called  Internal 
Nasal,  which  penetrates  from  the  orbit  into  the  cavity  of  the  cranium, 
through  the  anterior  internal  orbitary  foramen,  and  lies  covered  by 
the  dura  mater,  at  the  side  of  the  crista  galli ; thence  it  passes  into 
the  cavity  of  the  nose  through  the  most  anterior  foramen  of  the  crib- 
riform plate. 

The  Internal  Nasal  Nerve  ( Nasalis  Internus ) having  got  into  the 
nose  divides  into  two  fasciculi,  an  internal  and  an  external.  The 
internal  descends  along  the  anterior  margin  of  the  septum,  between 
the  mucous  membrane  and  the  bone,  and,  after  a short  course,  is 
divided  into  two  filaments,  one  of  which  applying  itself  to  the  pos- 
terior face  of  the  os  nasi,  terminates  by  smaller  filaments  in  the  in- 
teguments of  the  lower  part  of  the  nose ; the  other  filament  continues 
along  the  margin  of  the  septum  to  its  lower  part,  where  it  terminates 
by  smaller  filaments.  The  external  fasciculus  of  the  Nasalis  Inter- 
nus gives  off  early  a filament,  which  descends  along  a groove  on 
the  posterior  face  of  the  nasal  bone,  and  winding  over  the  lower 
edge  of  the  latter,  or  passing  through  a foramen  in  it,  is  lost  upon 
the  integuments  of  the  corresponding  part  of  the  nose.  Other  fila- 
ments from  the  external  fasciculus  descend  upon  the  mucous  mem- 
brane, along  the  external  anterior  part  of  the  nose  or  that  which 
corresponds  with  the  nasal  process  of  the  upper  maxilla,  and  termi- 
nate near  the  anterior  extremity  of  the  inferior  spongy  bone : they  are 
three  or  four  in  number.  The  internal  nasal  nerve  is  also  said  to 
send  one  or  more  filaments  to  the  frontal  sinus,  but  they  are  so  fine 
that  doubts  of  their  existence  are  entertained  by  Bichat,  though 
they  are  admitted  by  J.  F.  Meckeh 

Vol.  II.— 37 


426 


NERVOUS  SYSTEM. 


The  Spheno-Palatine  Ganglion,  a part  of  the  second  branch  of 
the  Trigeminus,  detaches  to  the  nose,  through  the  spheno-palatine 
foramen,  several  filaments.  One  of  these  discovered  by  Cotun- 
nius,  and  admirably  delineated  by  Scarpa  and  by  John  Hunter, 
called  the  Naso-Palatinus,  runs  across  the  front  of  the  sphenoidal 
sinus  to  the  upper  posterior  part  of  the  septum  narium,  beneath  the 
mucous  membrane.  It  then  descends  obliquely  along  the  septum 
to  the  foramen  incisivum,  and  passes  through  it  to  the  root  of  the 
mouth.  In  many  cases,  however,  a distinct  foramen  is  formed  in 
the  middle  palate  suture  for  it,  anterior  to  the  foramen  incisivum. 
The  nerve  of  the  left  side  is  anterior  to  that  on  the  right.  When 
the  two  reach  the  roof  of  the  mouth,  or  are  near  it,  they  unite  to 
form  a little  swelling  called  the  naso-palatine  ganglion,*  from 
which  several  filaments  arise,  and  are  spent  upon  the  membranous 
caruncle  at  this  point,  and  upon  the  contiguous  part  of  the  palatine 
membrane. 

The  spheno-palatine  ganglion  sends  several  filaments  to  the  mu- 
cous membrane  of  the  upper  spongy-bone  and  of  the  upper  meatus, 
and  to  that  of  the  posterior  end  of  the  middle  spongy  bone.  The 
palatine  nerve,  one  of  its  largest  branches,  in  descending  along  the 
posterior  palatine  canal  to  the  soft  palate  of  the  mouth,  also  contri- 
butes to  the  supply  of  nerves  to  the  nose.  Shortly  after  it  has  arisen 
from  the  ganglion,  it  sends  one  or  more  filaments  to  the  middle 
spongy  bone,  and  to  the  superior  part  of  the  lower  spongy  bone,  and 
when  it  has  got,  in  its  descent,  on  a level  with  the  posterior  end  of 
the  latter,  it  detaches  another  filament,  which  supplies  the  mucous 
membrane,  along  the  inferior  margin  of  this  bone. 

In  regard  to  the  termination  of  these  several  orders  of  nerves,  it  is 
generally  held  that  the  filaments  of  the  olfactory,  end  in  brush-like  ex- 
tremities. Klencke,f  however,  asserts  that  on  the  septum,  they  form 
distinctly  cylindrical  filaments,  ending  in  fine  loops,  while  elsewhere 
they  end  by  a very  delicate  capillary  net-work.  Huschke^  claims  to 
have  observed  the  arteries  of  the  Schneiderian  membrane  attended  by 
filaments  of  the  sympathetic,  and  has  advanced  the  opinion  that  the 
naso-palatine  nerve  is  itself  only  the  upper  end  of  the  great  sympa- 
thetic. It  is  probable  that  the  filaments  of  the  fifth  pair  belonging 
to  the  nose,  end  as  elsewhere  by  terminal  loops. 

An  opinion  advanced  by  Mery  about  the  close  of  the  seventeenth 


* J.  Cloquet,  Anat. 


t Iluscfoke,  loc.  cit.  p.  565. 


t Loc.  cit. 


THE  EYE. 


427 


century,  has  been  revived  by  M.  Magendie,  of  Paris,  that  the  olfactory 
nerves  are  not  those  which  communicate  the  impressions  of  odorous 
bodies.  In  contradiction,  however,  to  his  experiments,  it  should  be 
stated,  that  several  respectable  anatomists  have  seen  cases  where 
the  privation  of  the  sense  of  smell  during  life,  was  found,  upon  ex- 
amination after  death,  to  be  attended  with  the  absence  of  the  olfac- 
tory nerves. 


Of  the  Blood  Vessels  of  the  JVose. 

The  extreme  vascularity  of  the  Schneiderian  Membrane  is  derived 
from  several  sources.  The  Internal  Maxillary  Artery  sends  through 
the  Spheno-Palatine  Foramen  a large  branch,  which  is  distributed 
upon  the  septum  and  upon  the  spongy  bones  : The  superior  palatine 
artery  supplies  this  membrane  with  one  or  more  small  branches : 
The  Ophthalmic  also  sends  the  anterior  and  the  posterior  ethmoidal 
branches  to  it,  from  the  orbit  of  the  eye.  The  Infra-orbitar  artery 
likewise  contributes  to  its  vascularity  by  one  or  more  branches,  sent 
off  in  its  course  through  the  infra-orbitar  canal. 

The  veins  follow  the  course  and  distribution  of  the  arteries.  Some 
of  them,  however,  unite  with  the  trunks  called  emissaries  of  Santo- 
rini, which  come  from  the  sinuses  of  the  dura  mater  through  the 
foramen  ovale  and  rotundum  of  the  sphenoid  bone.  They  are  ex- 
tremely superficial  with  very  thin  parietes,  hence  they  bleed  from 
the  most  trivial  causes. 


CHAPTER  II. 

Of  the  Eye,  and  its  Dependencies. 

The  organ  of  vision  which  depends  upon  the  optic  nerve  for  its 
usefulness,  is  formed  by  the  Ball  of  the  Eye  and  many  Dependen- 
cies or  Auxiliary  parts,  all  of  which  are  situated  within  the  orbit, 
and  fill  up  its  cavity. 


428 


NERVOUS  SYSTEM. 


SECT.  I. — OF  THE  AUXILIARY  PARTS  OF  THE  EYE.* 

The  Eyelids  ( Palpebrce ) are  placed  at  the  anterior  orifice  of  the 
orbit,  and  serve  to  shut  out  the  light  from  the  eye,  by  their  closing; 
and  also,  by  their  frequent  motions,  to  sweep  the  front  of  the  eye- 
ball, so  as  to  remove,  from  its  transparent  part,  moats  and  dust. 
They  are  distinguished  into  upper  and  lower,  and  the  place  at  each 
end,  where  the  horizontal  fissure  between  them  ceases,  is  called  their 
Commissure,  Angle  or  Canthus.  The  angle  next  to  the  nose,  or 
the  internal,  is  called  the  Great  one,  and  the  other, the  Little  one. 

The  Internal  Canthus  is  united  to  the  nasal  process  of  the  supe- 
rior maxillary  bone  by  a rounded  tendon,  ( Li g amentum  Palpebrale 
Internum ,)  the  origin  of  the  orbicularis  palpebrarum  muscle  ; and 
which  passes  horizontally  inwards,  being  nearly  half  an  inch  in 
length.  It  throws  the  skin  into  a small  ridge,  which  may  be  dis- 
tinctly seen  and  felt  at  this  point.  The  External  Canthus  is  held 
in  place  by  its  general  attachments  of  cellular  substance  and  by  the 
external  palpebral  ligament. 

The  upper  eyelid  is  somewhat  larger  than  the  lower,  but  the 
structure  of  both  is  the  same,  for  each  one  is  formed  by  skin  exter- 
nally ; next  to  it  a plane  of  muscular  fibres,  being  the  orbicularis 
palpebrarum ; then  a plate  of  cartilage  ; and,  lastly,  a thin  mem- 
brane uniting  it  to  the  eyeball. 

There  is  nothing  in  the  texture  of  the  skin  of  the  eyelid  which 
needs  description  in  a manner  more  particular  than  that  of  stating 
its  fineness,  its  thinness,  the  looseness  of  its  attachment  to  the  mus- 
cle beneath  by  long  yielding  cellular  substance,  and  the  deficiency 
of  adipose  matter.  The  skin  is  rendered  prominent  at  the  superior 
margin  of  the  orbit,  both  by  the  projection  of  the  bone  there,  and  by 
the  presence  of  the  corrugator  supercilii  muscle  at  its  internal  extre- 
mity. This  prominence  is  furnished  with  an  arched  cluster  of  hairs, 
( Supercilia ,)  which  have  their  loose  ends  inclined  horizontally  out- 
wards, and  are  rather  more  abundant  at  the  root  of  the  nose  than  ex- 
ternally. The  supercilia  of  the  two  sides  are  separated  commonly 
by  a small  bare  space  called  Glabella,  the  existence  of  which  adds 
much  to  the  calm  and  intellectual  expression  of  the  human  counte- 


Anat.  Atlas,  Figs.  558  to  56!,  inclusive. 


THE  EYE. 


429 


nance  ; whereas,  the  junction  of  the  two  eyebrows,  by  the  hairs 
filling  up  this  space,  gives  a gloomy,  and  occasionally,  a ferocious 
appearance. 

The  margins  of  the  eyelids  are  also  furnished  with  hairs,  {Cilia) 
the  roots  of  which  are  insinuated  between  the  skin  and  the  tarsi  car- 
tilages: the  most  deeply  seated  seem,  indeed,  to  penetrate  the  latter. 
The  hairs  of  the  upper  lid  are.  longer  and  more  numerous  than  those 
of  the  lower:  they  are  concave  upwards,  while  the  latter  are  con- 
cave downwards,  so  that  the  convexities  of  the  two  ranges  of  hairs 
come  in  contact  when  the  eyelids  are  closed.  The  hairs  of  each 
cilium  are  disposed  into  three  or  four  rows,  by  which  a long  brush 
is  formed,  the  central  hairs  of  which  are  longer  and  larger  than  any 
others. 

The  hairs  of  the  supercilia  and  of  the  cilia  resemble  one  another 
strongly,  for,  when  examined  closely,  each  one  will  be  found  to 
have  a bulbous  soft  root,  just  beyond  which  there  is  a narrow  part. 
The  middle  of  the  hair  is  swollen,  and  its  external  extremity  is 
brought  to  a fine  point.  These  hairs  correspond  in  colour  with  the 
hairs  of  the  head. 

• When  the  orbicularis  muscle  is  removed,  a ligamentous  or  fibrous 
membrane  is  found  passing  from  the  external  margin  of  the  orbit  to 
the  corresponding  margin  of  the  palpebral  cartilages,  and  separating 
the  eyelids  from  the  parts  contained  within  the  orbit.  There  is  a 
partial  decussation  of  the  fibres,  of  this  membrane,  from  the  external 
commissure  of  the  cartilages  to  the  adjoining  edge  of  the  orbit ; it 
has  more  firmness  than  any  other  part  of  the  membrane,  and  is  the 
external  palpebral  ligament,  {Ligcimentum  Palpebrale  Externum.) 
On  the  side  of  the  internal  canthus  of  the  orbit  there  is  no  corres- 
ponding ligamentous  expansion,  but  a few  irregular  fibres,  which 
allow  the  masses  of  fat  beneath,  to  project  forwards  between  their 
fasciculi. 

The  Palpebral  Cartilages  ( Tarsi ) are  two  in  number,  one  at  the 
margin  of  each  eyelid,  to  which  they  communicate  a smooth,  even 
surface,  from  the  internal  to  the  external  commissure.  They  are 
between  the  orbicularis  muscle  and  the  tunica  conjunctiva.  The 
upper  one  is  larger  than  the  lower,  resembles  an  oval  cut  in  half  in 
its  long  diameter,  and  is  about  six  lines  broad  in  its  middle : the 
lower  one  is  of  a breadth,  nearly  uniform,  of  about  two  lines.  Their 
internal  extremities  cease  just  before  they  reach  the  puncta  lachry- 

37* 


430 


NERVOUS  SYSTEM. 


malia,  and  are  attached  to  the  internal  palpebral  ligament ; which 
has  just  been  described  as  one  of  the  origins  of  the  orbicularis  oculi 
muscle,  at  the  nasal  process  of  the  upper  maxillary  bone ; their  ex- 
ternal extremities  cease  just  before  their  commissure,  and  are  firmly 
attached  to  the  external  palpebral  ligament. 

These  cartilages  are  thicker  where  they  form  the  margin  of  the 
eyelids,  and  have  there  a slope  or  bevel,  by  which,  when  in  contact, 
a small  groove  is  formed  on  their  posterior  surface.  From  their  re- 
sistance to  the  concentric  contractions  of  the  orbicularis,  they  keep 
the  eyelid  smooth,  and  favour  its  sliding  upon  the  eyeball.  Certain 
animals,  being  destitute  of  these  cartilages ; when  they  wink,  the 
skin,  by  the  contraction  of  the  orbicularis,  is  drawn  up  like  the 
mouth  of  a purse. 

Conjunctiva. — Below  the  palpebral  cartilage  is  the  fourth  layer  of 
the  eyelid,  the  conjunctiva.  It  is  a white,  thin  and  diaphanous 
membrane,  in  the  uninflamed  state.  Beginning  at  the  roots  of  the 
cilia,  where  it  is  continuous  with  the  skin,  it  covers  the  posterior 
face  of  the  eyelids  in  adhering  almost  immoveably  to  the  tarsi  carti- 
lages ; is  reflected  for  eight  or  ten  lines  towards  the  bottom  of  the 
orbit,  and  then  passes  to  the  eyeball,  of  which  it  covers  the  anterior 
half,  not  excepting  the  cornea.  At  the  circumference  of  the  latter  it 
suffers  a little  circular  elevation  called  the  annulus  conjunctivae.  Its 
reflection  towards  the  bottom  of  the  orbit  is  two  or  three  lines  deeper 
in  the  case  of  the  upper  than  the  lower  lid.  It  penetrates  into  the 
lachrymal  passages,  to  be  continuous  with  the  lining  membrane  of 
the  lachrymal  sac. 

From  this  description,  it  is  evident  that  the  tunica  conjunctiva  has 
one  surface  presented  against  itself  when  the  eyelids  are  closed  ; this 
surface  is  lubricated  and  very  smooth,  so  as  to  permit  a free  motion 
of  the  lids  and  ball  of  the  eye.  The  other  surface  is  connected  in 
its  anterior  half  by  cellular  substance  to  the  eyelids,  and  in  its  re- 
maining part  to  the  ball  of  the  eye,  by  the  same  means.  The  name 
of  the  sclerotic  fascia  has  latterly  been  used  to  designate  this  cellular 
substance,  and  is  especially  resorted  to  in  the  account  of  operations 
for  squinting,  by  cutting  the  muscles  of  the  eyeball.  This  fascia, 
ar  cellular  tissue,  may  be  traced  to  the  bottom  of  the  orbit  at  the 
optic  foramen,  and  makes  an  investment  of  the  several  contents  of  the 
orbit.  From  this  it  is  sometimes  considered  as  consisting  of  two 
iaminm  ; the  exterior  one  being  an  investment  especially  of  the  mus- 


THE  EYE. 


431 


cles,  is  the  capsule  of  Bonnetus ; while  the  more  interior  division 
being  next  to  the  globe  of  the  eye,  is  the  capsule  of  Tenon.  The 
conjunctiva  is  united  rather  loosely  to  the  sclerotica  till  it  gets  near 
the  margin  of  the  cornea ; but  to  the  latter  it  adheres  so  firmly,  and 
changes  there  so  much  in  its  texture,  that  it  seems  like  a portion  of 
the  cornea. 

This  membrane  from  its  continuity  with  the  skin  and  the  lining 
membrane  of  the  nose,  from  its  sympathies  with  them,  from  the 
nature  of  the  discharge  from  it,  and  from  its  extreme  sensibility,  is 
ranked  by  Bichat  among  the  mucous  membranes.  It,  has,  how- 
ever, some  peculiarities  in  its  structure,  for  it  is  entirely  deficient  in 
villosities  on  the  eyeball,  unless  near  the  angle  of  reflection — but  on 
the  eyelids,  and  especially  the  palpebral  cartilages,  the  villosities  are 
very  easily  seen  in  an  inflamed  state  or  when  erected  by  an  injection. 
The  conjunctiva  is  most  abundantly  furnished  with  capillary  ves- 
sels, and  they  do  not  obviously  admit  red  blood,  but  in  a state  of  ir- 
ritation ; except  just  among  the  glands  of  Meibomius,  where  most 
persons  have  them  somewhat  turgid  with  blood.  In  a minute  injec- 
tion, this  vascularity  is  fully  and  beautifully  evolved  on  the  tarsi 
cartilages. 

The  conjunctiva  has  a covering  of  Epithelium,  and  is  stated  by 
Valentin*  to  be  destitute  of  mucous  follicles,  the  secretion  of  the 
lachrymal  gland  supplying  the  place  of  mucus.  This  observation  is, 
however,  opposed  to  that  of  Krause,  who  says  that  they  are  very 
numerous  at  the  conjunctival  reflection  ; forming  little  masses  there, 
and  then  scattering  as  they  approach  the  tarsi  cartilages.  Its  epi- 
thelium is  made  according  to  Henle,  of  fine  polyhedral  nucleated 
cells. 

Glandules  Palpebrarum. — These  bodies  also  called  the  glands  of 
Meibomius,  from  an  anatomist  who  has  described  them  particularly, 
are  situated  at  the  margin  of  each  eyelid ; between  its  cartilage,  in 
which  they  are  received  in  small  grooves,  and  the  conjunctiva. 
They  are  about  two  or  three  lines  long,  and  appear  like  small, 
white,  serpentine  threads,  running  at  right  angles' to  the  margin  of 
the  lid,  near  to,  and  parallel  with  one  another.  When  examined 
closely  it  will  be  found  that  a Gland  of  Meibomius  is  a long  tube 
having  small  ececal  tubes  or  cells  discharging  into  its  sides,  and 


* Muller’s  Physiol.,  p,  417.  Lond.,  1840. 


432 


NERVOUS  SYSTEM. 


which  occasion  the  serpentine  appearance.  They  are  more  abun- 
dant on  the  upper  than  on  the  lower  lid.  They  terminate  by  a row 
of  small  orifices  in  the  margin  of  the  lid,  just  behind  the  cilia.  For 
preventing  the  overflowing  of  the  tears,  and  the  sticking  together  of 
the  eyelids,  they  discharge  an  unctuous  fluid,  which  may  be  made 
manifest  by  squeezing  them.  Their  secretion  is  occasionally  much 
augmented,  and  then  has  a large  quantity  of  serum  and  glutinous 
matter  in  it : in  this  case  the  evaporation  of  the  serum  makes  it  ad- 
hesive, and  causes  the  eyelids  to  adhere  after  they  have  been  elosed 
for  some  time,  as  in  sleep. 

The  Lachrymal  Caruncle  ( Caruncula  Laclirymalis ) is  placed  in 
the  angle  formed  by  the  internal  junction  of  the  eyelids.  It  is  a red- 
coloured  tubercle,  differing  in  size  in  different  individuals,  but 
commonly  as  large  as  a grain  of  wheat.  It  is  conical,  and  obtains 
its  redness  from  the  conjunctiva  being  reflected  over  it  r when  ac- 
curately examined,  it  will  be  found  to  consist  in  a group  of  sebaceous 
glands;  of  which  according  to  some  anatomists,  there  are  seven 
ranged  two  in  a row,  and  one  on  the  top  of  the  others.  The  sur- 
face of  this  body  is  beset  with  very  fine  hairs,  and  the  orifices  in  if 
are  distinguishable  with  a glass. 

The  Semilunar  Valve,  or  Fold,  ( Plica  Semilunaris ,)  is  situated 
immediately  at  the  outer  margin  of  the  caruncle.  It  has  the  form  of 
a triangle,  the  point  of  which  runs  into  the  caruncle,  and  the  base, 
which  is  somewhat  crescentic,  is  directed  towards  the  eye.  It  is  a 
duplicature  of  the  conjunctiva;  becomes  very  manifest  in  an  exami- 
nation from  behind,  and,  in  some  persons,  has  its  base  furnished 
with  a very  small  strip  of.  cartilage.*  I have  seen  several  cases  of 
the  kind  very  well  marked ; they  occur  more  frequently  in  the 
African,  according  to  my  personal  experience.  Between  the  base 
and  the  caruncle  this  fold  is  formed  into  a number  of  small  loose 
wrinkles,  which  disappear  when  the  eye  is  very  much  abducted. 

This  body,  in  the  human  subject,  is  evidently  intended  to  permit 
to  the  eye  a great  freedom  of  abduction.  Its  analogy,  however, 
with  the  third  eyelid  of  animals  is  very  striking,  and  the  difference 
is  rather  in  the  full  development  of  the  latter,  than  in  the  organiza- 
tion. It  is  very  properly  remarked  by  J.  F.  Meckel,  that  in  de- 


* Meckel. 


THE  EYE. 


433 


scending  the  scale  of  animals,  the  third  eyelid  is  always  in  an  in- 
verse ratio  to  the  other  two,  till  it  ends  by  being  a complete  substitute 
for  them. 

Surrounding  the  Lachrymal  caruncle  may  be  observed  a de- 
pression on  the  adjoining  part  of  the  plica  semilunaris.  Into  this 
depression  the  puncta  lachrymalia  are  directed,  and  there  play  up 
and  down.  The  tears  accumulate  in  it ; from  which  cause  the  de- 
pression is  called  Lacus  Lachrymalis. 

Muscles. 

The  Musculus  Levator  Palpebrae  Superioris  is  placed  in  the  su- 
perior part  of  the  orbit.  It  arises  by  a small  round  tendon  from  the 
upper  margin  of  the  optic  foramen,  and,  becoming  fleshy,  it  ex- 
pands itself  into  a long  thin  triangle,  of  which  the  base  is  in  front. 
It  covers  the  rectus  superior  muscle. 

Terminating  in  front  by  a thin  tendinous  expansion,  it  is  inserted 
into  the  superior  margin  of  the  upper  palpebral  cartilage ; but  some 
of  its  fibres  continue  on  between  the  latter  and  the  orbicularis  to  the 
lower  edge  of  the  cartilage. 

It  raises  the  upper  lid,  by  drawing  it  towards  the  bottom  of  the 
orbit. 

There  are  six  muscles  concerned  in  moving  the  eyeball,  four  of 
which,  from  their  direction  are  said  to  be  straight ; and  the  other 
two,  for  the  same  reason,  are  called  oblique.  With  the  exception 
of  the  inferior  oblique,  they  all  arise  from  the  bottom  of  the  orbit. 
Being  inserted  tendinously  into  the  Sclerotica,  their  tendons  pass  on 
for  two  lines  or  so  in  continuing  this  connexion  beyond  its  com- 
mencement. 

1.  The  Rectus  Oculi  Superior,  being  placed  immediately  below 
the  levator  palpebrae,  arises  from  the  superior  margin  of  the  optic 
foramen.  It  runs  forwards,  increasing  somewhat  in  breadth,  and 
is  inserted  by  a broad  thin  tendon  into  the  sclerotica,  four  lines  from 
the  cornea. 

It  turns  the  eye  upwards. 

2.  The  Rectus  Oculi  Externus  arises  from  the  external  margin  of 


434 


NERVOUS  SYSTEM. 


the  optic  foramen.  It  then  advances  along  the  middle  of  the  ex- 
ternal wall  of  the  orbit,  near  the  periosteum,  to  which  it  adheres 
slightly ; and  is,  finally,  inserted,  by  a thin  broad  tendon,  into  the 
external  side  of  the  sclerotica,  about  four  lines  from  the  cornea. 

It  abducts  the  eye,  or  turns  it  outwards. 

3.  The  Rectus  Oculi  Inferior  arises  also  from  the  optic  foramen, 
at  its  inferior  margin,  and,  lies  upon  the  floor  of  the  orbit  as  it  ad- 
vances forwards.  It  is  inserted,  tendinous,  into  the  under  surface  of 
the  sclerotica,  three  lines  from  the  cornea. 

It  depresses  the  eye,  or  turns  it  downwards. 

4.  The  Rectus  Oculi  Internus  arises  from  the  internal  margin  of 
the  optic  foramen,  and  goes  forwards  along  the  internal  wall  of  the 
orbit,  being  separated  from  it  by  a layer  of  adipose  matter.  It  is 
inserted,  by  a tendinous  expansion,  into  the  inner  side  of  the  scle- 
rotica, three  lines  from  the  cornea. 

It  adducts  the  eye,  or  turns  it  inwards. 

5.  The  Obliquus  Oculi  Superior  is  placed  along  the  upper  in- 
ternal angle  of  the  orbit.  It  arises  from  the  corresponding  margin 
of  the  optic  foramen,  by  a small  round  tendon ; it  then  advances 
forwards,  and  when  it  has  got  near  the  margin  of  the  orbit,  it  is  con- 
verted into  a long  round  tendon. 

The  tendon  passes  through  a fibro-cartilaginous  loop  which  is 
formed  for  it,  just  at  the  inner  margin  of  the  supra  orbitary  foramen, 
and  is  connected  to  the  loop  by  long  loose  cellular  substance,  which 
permits  it  to  play  freely  backwards  and  forwards.  The  tendon  from 
this  point  changes  its  direction  by  going  backwards  and  outwards ; 
it  also  becomes  more  flat,  and  is  then  inserted  into  the  upper  face 
of  the  sclerotica  near  its  middle,  just  beneath  the  internal  margin  of 
the  rectus  superior  muscle. 

This  muscle  is  the  longest,  but  the  most  delicate  of  those  belong- 
ing to  the  eyeball.  According  to  Soemmering  it  draws  “ the  eye-ball 
forwards,  and  towards  the  internal  canthus,  and  directs  the  pupil 
towards  the  cheek.  By  the  aid  of  the  inferior  oblique,  it  draws  the 
eyeball  towards  the  nose  : it  expresses  pride  : it  appears  to  be  greatly 
excited  in  anger.”* 

* Bulbum  in  priora  et  angulum  internum  versus  niovet;  pupillam  deorsum  ad 
genam  dirigit ; juvante  musculo  obliquuo  inferiore  bulbum  nasum  versus  traliit ; 
animi  fastum  exprimit;  ira  valde  commoveri  videtur. 


THE  EYE. 


435 


The  preceding  muscles  are  all  connected,  either  directly  or  in- 
directly, with  the  theca  of  the  optic  nerve. 

6.  The  Obliquus  Oculi  Inferior  is  at  the  bottom  of  the  orbit. 

It  arises,  by  a small  tendinous  beginning  from  the  os  maxillare 
superius  at  the  side  of  the  os  unguis,  and,  increasing  in  size,  it  goes 
below  the  rectus  inferior  outwards  and  backwards,  and  gets  between 
the  eyeball  and  the  rectus  externus.  It  is  then  inserted  into  the 
outer  face  of  the  sclerotica,  about  half  way  between  the  optic  nerve 
and  the  cornea. 

It  causes  the  eye  to  revolve  on  its  axis,  and  turns  the  cornea  to- 
wards the  nose.  Its  action,  howrever,  is  much  modified  by  that  of 
the  other  muscles. 

As  the  revolving  axis  of  the  eye  is  a line  passing  from  the  centre 
of  the  optic  nerve,  forwards  and  outwards,  it  will  be  found  that  each 
of  the  oblique  muscles  is  inserted,  at  right  angles,  to  this  line.  Con- 
sequently, their  simple  and  unmodified  action  is  to  produce  a revo- 
lution of  the  eye  on  its  axis,  in  the  line  of  their  insertion ; the  first 
making  the  eye  roll  inwards,  and  the  latter  outwards,  on  the  two 
poles;  they,  therefore,  are  strictly  antagonists. 


Of  the  Lachrymal  Apparatus* 

The  apparatus  for  the  tears  ( Organa  Lachrymalia,  vice  Lachry- 
males)  consists  in  the  Lachrymal  Gland,  the  Lachrymal  Ducts,  the 
Lachrymal  Sac,  and  a few  other  parts. 

The  Lachrymal  Gland  ( Glandula  Lachrymalis)  is  situated  in  the 
orbit,  immediately  below  and  within  the  external  angular  process  of 
the  os  frontis.  It  secretes  the  moisture  that  lubricates  the  eyelids 
and  eyeball,  and  which,  when  it  becomes  abundant,  is  called  the 
Tears.  It  is  a flattened  oblong  or  oval,  convex  above  and  concave 
below,  of  ten  lines  in  length,  six  in  wudth,  and  about  twro  lines  at 
its  thickest  part,  for  its  edges  are  somewhat  bevelled.  It  may  be 
considered  as  divided  into  two  parts  or  lobes,  of  which  the  superior 
is  the  larger  and  occupies  the  depression  attributed  to  it  in  the 
frontal  bone,  while  the  inferior,  being  the  smaller,  is  placed  at  the 


Amt.  Atlas,  Fig.  562. 


436 


NERVOUS  SYSTEM. 


anterior  margin  of  the  depression.  It  is  lined  below  by  the  con- 
junctiva, and  is  protected  in  front  by  the  margin  of  the  orbit  which 
it  touches.  These  lobes  are  frequently  marked  off  by  a ligamentous 
band  passing  from  between  them  to  the  external  angular  process, 
and  called  by  Soemmering,  Ligamentum  Gland.  Lachrymalis. 

This  gland  resembles  much  a salivary  gland  in  its  light  pink 
colour,  and  in  its  consisting  in  a congeries  of  lobules  united  by 
cellular  substance.  Unless  we  are  to  consider  the  latter  as  such,  it 
has  no  regular  capsule.  From  the  lachrymal  gland  there  proceed 
six  or  seven  excretory  canals,  extremely  fine,  and  found  with  so 
much  difficulty  that  many  distinguished  anatomists  have  sought  for 
them  in  vain.*  The  orifices  of  these  ducts  have  been  laid  down 
by  Soemmering,  as  equi-distant ; forming  in  the  conjunctiva,  a row 
half  an  inch  long,  and  parallel  with  the  superior  margin  of  the  upper 
tarsus  cartilage,  beginning  a quarter  of  an  inch  above  its  external 
end  and  going  inwards.  By  squeezing  the  gland,  small  drops  like 
tears,  will  appear  on  the  nearest  surface  of  the  conjunctiva,  but  not 
in  the  regular  order  laid  down  by  anatomists  for  the  lachrymal  ori- 
fices. 

The  Lachrymal  Ducts  ( Canaliculi  Lachrymales ) are  situated  im- 
mediately beneath  the  skin,  at  the  internal  commissure  of  the  eyelids, 
in  their  posterior  margin,  and  behind  the  orbicularis  muscle.  There 
is  one  for  each  eyelid.  They  are  about  half  an  inch  long,  though 
the  lower  one  is  rather  longer  than  the  upper. 

The  lachrymal  ducts  commence  at  a small  elevation  of  the  margin 
of  each  eyelid,  bordering  immediately  upon  the  internal  end  of  the 
tarsus  cartilage,  but  perfectly  distinct  from  it.  This  elevation  is 
conical,  has  a vermicular  motion  during  life  from  a special  muscular 
arrangement,  and  points  towards  the  ball  of  the  eye;  in  its  centre 
is  a very  small  foramen,  called  the  Punctum  Lachrymale,  which  is 
the  beginning  of  the  lachrymal  duct.  The  punctum  is  about  a line 
in  length ; and  enlarging  in  its  course,  it  runs  at  right  angles  to  the 
duct  into  which  it  empties,  and  of  which  it  may  be  called  the  Orbital 

* These  are  Morgagni,  Haller,  Zinn,  and  Duverney.  Meckel,  Soemmering,  and 
many  others,  speak  with  all  confidence  concerning  them.  Bichat  admits  that  he 
only  acknowledges  their  existence  inductively.  Dr.  Monro,  of  Edinburg,  claims  to 
have  discovered  them  by  plunging  the  eye  into  a coloured  fluid  which  was  absorbed 
by  them.  Dr.  W.  Hunter  seems  to  have  a prior  claim  to  Dr.  Monro.  See  Med. 
Comment,  p.  54.  Mascagni  also  acknowledges  their  existence: — Prodromo  della 
Grande  Anatomia,  vol.  i.  p.  60. 


THE  EYE. 


437 


Orifice : the  upper  one  will,  therefore,  ascend,  and  the  lower  one 
descend. 

The  lachrymal  ducts  are  much  larger  than  the  puncta,  and  are  in 
their  whole  course  about  one  line  in  diameter.  At  their  orbital  ex- 
tremities, they  go  rather  beyond  the  puncta,  so  as  to  form  a small 
cul-de-sac.  These  canals  converge,  and  having  got  to  the  internal 
angle  of  the  eyelid,  they  are  there  placed  behind  the  internal  palpe- 
bral ligament.  They  then  discharge,  by  distinct  orifices,  but  very- 
near  each  other,  into  the  lachrymal  sac  at  its  external  anterior 
part.  At  the  place  of  their  entrance  there  is  a small  spheroidal  ex- 
cavation or  sinus  into  which  they  empty,  the  free  edges  of  which 
make  a circular  doubling,  apt  to  arrest  an  instrument  in  its  passage 
from  the  punctum  to  the  Lachrymal  sac.  Where  they  enter  they 
form  a small  round  projection  into  the  interior  of  this  cavity.  When 
the  eyelids  are  closed,  the  lachrymal  ducts  are  horizontal  and  nearly 
parallel,  but  when  the  eye  is  open  the  duct  is  elevated,  and  thereby 
becomes  oblique ; it  is  hence  more  proper  for  the  introduction  of  in- 
struments into  the  lachrymal  sac. 

The  Lachrymal  Sac  ( Saccus  Lachrymalis ) is  placed  at  the  internal 
canthus  of  the  orbit ; in  the  depression  of  the  os  unguis,  and  of  the 
nasal  process  of  the  upper  maxillary  bone.  It  is  an  oblong  cylin- 
droid  cavity,  and  extends  from  the  transverse  facial  suture  to  the 
anterior  extremity  of  the  inferior  meatus  of  the  nose  ; being  concealed 
there  by  the  anterior  part  of  the  inferior  turbinated  bone.  It  is 
crossed  at  its  front  part  by  the  tendon  of  the  orbicularis,  which,  w’ith 
a few  fibres  of  this  muscle,  adheres  to  it. 

The  course  of  the  lachrymal  sac  is  at  first,  slightly  forwards  in  the 
descent  to  the  nose ; but,  when  it  reaches  the  lower  part  of  the  orbit, 
it  is  afterwards  slightly  backw-ards:  so  that  it  may  be  considered  as 
forming  an  obtuse  angle  forwards.  It  also  decreases  somewhat  in 
size  from  above  downwards,  and  at  its  lower  orifice  is  flattened  from 
side  to  side. 

The  lachrymal  sac  Consists  in  two  membranes ; an  exterior  fibrous 
one  continuous  with  the  periosteum  of  the  contiguous  bones,  and  an 
interior  mucous  one,  which  is  thick,  villous,  of  a red  colour,  from 
the  abundance  of  its  blood  vessels;  and  abounding  in  mucous  folli- 
cles or  glands.  The  interior  is  continuous  above  with  the  lachrymal 
ducts,  and  below  with  the  Schneiderian  membrane.  On  a line  with 
the  floor  of  the  orbit,  this  internal  membrane  is  thrown  into  a circular 
Vol.  II.— 38 


438 


NERVOUS  SYSTEM. 


duplicature,  considered  by  some  anatomists  as  forming  the  proper 
boundary  of  the  lachrymal  sac:  all  below  this  is  called  by  them 
Nasal  Canal , (Ductus  ad  Nasum.)  The  distinction  is  rather  arbi- 
trary, and,  in  some  degree,  hurtful  to  clearness  of  description:  a 
much  better  plan  is  to  call  the  part  above  the  valve  the  orbital  por- 
tion of  the  sac,  and  the  part  below  the  valve  its  nasal  portion.  Some- 
times there  is  a second  valve  about  three  lines  below  the  first,  and 
generally  another  at  the  nasal  orifice,  formed  by  a duplication  of  the 
Schneiderian  membrane.  This  is  either  circular  or  consists  of  two 
semi-elliptical  folds,  the  diameters  of  which  come  into  contact;  the 
slit  between  them  being  vertical.  • 

The  Tensor  Tarsi  is  a small  muscle  on  the  orbital  face  of  the 
lachrymal  sac,  and  of  which  I gave  a detailed  account  some  years 
ago.*  It  arises  from  the  posterior  superior  part  of  the  os  unguis, 
just  in  advance  of  the  vertical  suture  between  the  os  planum  and 
the  os  unguis.  Having  advanced  three  lines,  it  bifurcates ; one 
bifurcation  is  inserted  along  the  upper  lachrymal  duct,  and  termi- 
nates at  its  punctum,  or  near  it;  and  the  lower  bifurcation  has  the 
same  relation  to  the  lower  lachrymal  duct.  The  base  of  the  carun- 
cula  lachrymalis  is  placed  in  the  angle  of  the  bifurcation.  The 
superior  and  the  inferior  margin  of  the  muscle  touch  the  corre- 
sponding fibres  of  the  orbicularis  palpebrarum,  where  the  latter  is 
connected  with  the  margin  of  the  internal  canthus  of  the  orbit ; but 
may  be  readily  distinguished  by  their  horizontal  course.  The  nasal 
face  of  this  muscle  adheres  very  closely  to  that  portion  of  the  sac  which 
it  covers,  and  also  the  lachrymal  ducts.  The  lachrymal  sac  rises 
about  a line  above  its  superior  margin,  and  extends  in  the  orbit  four 
lines  below  its  inferior  margin.  The  orbital  face  of  the  muscle  is 
covered  by  a lamina  of  cellular  membrane,  and  between  this  lamina 
and  the  ball  of  the  eye  are  placed  the  valvula  semilunaris,  and  a con- 
siderable quantity  of  adipose  matter.' 

As  the  bifurcated  extremities  of  the  muscle  follow  the  course  of 
the  lachrymal  ducts,  they  are  covered  by  the  tunica  conjunctiva. 
When  this  muscle  is  examined  from  behind,  the  eyelids  being  in 
situ,  it  becomes  obvious  that  it  is  concave  on  its  orbital  surface, 
and,  consequently,  convex  on  the  nasal ; that  the  muscle  is  an  ob- 
long body,  half  an  inch  in  length,  and  about  three  lines  wide,  bifur- 

* Philadelphia  Journal  of  Med.  and  Phys.  Sciences,  1824.  Anat.  Atlas,  Fig.  172. 


THE  EYE. 


439 


cated  at  one  end : and  that  it  arises  much  deeper  from  the  orbit  than 
any  acknowledged  origin  of  the  orbicularis.  The  superior  fork,  how- 
ever, has  a few  of  its  fibres  blended  with  the  orbicularis. 

In  regard  to  the  use  of  this  muscle : its  attachment  to  the  poste- 
rior face  of  the  sac  is  such,  that  it  draws  the  orbital  part  of  the  sac 
away  from  the  nasal,  and  dilates  the  sac,  from  the  nasal  face  of 
the  latter  being  fixed  to  the  bones.  As  this  muscle  is  cylindrically 
concave  on  its  orbital  side,  it  is  evident  that  when  it  contracts,  the 
fibres  become  straight,  or  nearly  so,  like  the  fibres  of  the  diaphragm, 
and  the  cavity  of  the  sac  is  enlarged  after  the  same  manner  as  the 
cavity  of  the  thorax.  A tendency  to  a vacuum  being  thus  produced 
by  it,  the  valves  or  folds  of  the  internal  membrane  of  the  sac  resist 
so  that  the  vacuum  is  filled  more  readily  from  the  puncta,  than  from 
the  nose;  and  the  puncta  being  continually  bathed  in  the  tears 
of  the  lacus  lachrymalis,  both  in  the  waking  and  in  the  sleeping 
state,  the  tears  are  constantly  propelled  through  them  by  atmospheric 
pressure.  The  evacuation  of  the  sac  is  no  doubt  accomplished  by 
its  own  elasticity,  and  by  the  contraction  of  the  orbicularis  ; probably 
in  a chief  degree  by  the  latter,  because  in  persons  who  have  epiphora, 
or  a tendency  to  obstruction  in  the  nasal  duct,  the  accumulation  of 
tears  and  matter  principally  takes  place  at  night,  when  the  action  of 
the  orbicularis  is  suspended  by  sleep.  For  these  reasons,  we  should 
argue  that  this  little  muscle  is  active  at  all  times,  both  night  and 
day.  To  Dr.  Physick  I am  indebted  for  suggesting  anothex  use  for 
it ; to  wit,  that  of  keeping  the  lids  in  contact  with  the  ball  of  the  eye. 

Some  persons  possess  unusual  voluntary  power  over  this  muscle, 
of  which  I have  seen  several  examples.  In  each  instance  the  indi- 
vidual could  shorten  so  much  the  internal  angle  of  the  eyelids,  as  to 
conceal  it,  along  with  the  puncta,  in  the  internal  canthus  of  the  orbit,* 

* Having  laboured,  first  of  all,  to  convince  the  profession  of  the  existence  of  this 
muscle,  the  next  step,  as  is  usual  on  such  occasions,  was  to  vindicate  my  own  pre. 
tensions  to  its  discovery  and  to  attempt  to  remove  such  objections  as  required 
attention.  For  the  arguments  on  this  subject,  see  the  Philadelphia  Journal  of 
Medical  and  Physical  Sciences,  of  Nov.,  1824,  edited  by  Professor  Chapman.  My 
claims  have  been  unequivocally  admitted  by  Messrs.  Breschet  and  Jourdan,  of  Paris, 
anatomists  of  unusual  distinction,  in  the  translation  which  they  have  made  of  J.  F. 
Meckel’s  Manual  of  Anatomy,  vol.  iii.,  p.  219  ; by  Gery,  in  the  Melanges  de  Chi- 
rurgie  etrangere,  Geneva,  1824,  pf  415 ; and  by  Professor  Giuseppe  Trasmondi,  in 
the  Arcadica  Journal  of  Rome,  &e.  vol,  xix.,  p.  1,  1823.  This  muscle  is  also  now 
admitted  into  the  myology  of  the  most  classical  works  on  Anatomy,  the  highest  of 
which  may  be  considered  the  latest  edition  of  Soemmering,  de  Corp,  Hum.  Fabr., 
under  the  title  of  Encyclopedie  Anatomique,  Paris,  1843. 


440 


NERVOUS  SYSTEM. 


Of  the  JYerves  of  the  Orbit. 

In  addition  to  the  optic  nerve,  there  are  several  belonging  to  the 
eye  and  to  its  auxiliary  parts ; they  are  derived  from  the  Motor 
Oculi  or  third  pair;  from  the  Trochlearis,  or  fourth  pair  ; from  the 
first  branch  of  the  Trigeminus,  or  fifth  pair;  and  from  the  Motor 
Oculi  Externus,  or  sixth  pair.  For  an  account  of  which  see 
Nerves, 


Of  the  Arteries  of  the  Orbit . 

The  Eyeball,  and  its  auxiliary  parts,  are  principally  supplied  by 
the  Ophthalmic  Artery,  which,  as  was  mentioned  in  the  account  of 
the  Brain,  is  a considerable  branch  given  off  by  the  Internal  Caro- 
tid at  the  fore  part  of  the  Sella  Turcica.  This  branch  gets  into  the 
orbit  on  the  outer  side  of  the  optic  nerve  through  the  optic  foramen, 
and,  after  a short  course,  crosses  obliquely  above  the  optic  nerve,  so 
as  to  pass  to  the  internal  side  of  the  orbit.  It  sends  off  a great  many 
small  trunks,  which  are  very  inconstant  both  in  their  size  and  origin  ; 
they  are  the  following: — 

1.  Arteria  Lachrymalis  arises,  commonly,  soon  after  the  oph- 
thalmic has  got  into  the  orbit ; it  goes  forwards  between  the  rectus 
superior  and  the  rectus  externus  muscle,  to  which  it  distributes  arte- 
rioles; it  then  reaches  the  lachrymal  gland,  and  having  left  branches 
with  it,  what  remains  issues  out  at  the  external  angle  of  the  eye, 
so  as  to  supply  the  contiguous  part  of  the  upper  eyelid. 

2.  Arterise  Ciliares.  According  to  Soemmering,  before  the  ori- 
gin of  the  lachrymal  artery,  the  ophthalmic  detaches  from  one  to  the 
three  ciliary,  which  penetrate  into  the  ball  of  the  eye  near  the  optic 
nerve.  Other  arteries  of  the  same  class  arise  subsequently  from  the 
ophthalmic,  and,  occasionally  some  of  them  from  the  lachrymal  itself. 
They  go  to  the  ehoroid  coat  of  the  eyeball  and  to  the  iris. 

3.  The  Arteria  Centralis  Retinse  arises  from  among  the  cluster 
of  ciliary  arteries,  and  like  them,  has  no  invariable  root.  It  pene- 
trates the  optic  nerve  about  the  middle  of  its  orbitar  portion,  and, 


THE  EYE. 


441 


going  in  its  centre,  gets  into  the  eye  through  the  cribriform  part  of 
the  sclerotica.  It  is  then  distributed  by  ramuscules  to  the  retina,  to 
the  tunica  hyaloidea,  and  to  the  capsule  of  the  lens. 

4.  The  Arteria  Ethmoidea  Posterior  is  inconstant  in  existence, 
and  comes  at  one  time  from  the  trunk,  at  another  from  a branch  of 
the  ophthalmic.  It  passes  over  the'  superior  oblique  muscle,  and 
penetrating  through  the  posterior  orbitary  foramen,  is  spent  by  arte- 
rioles upon  the  neighbouring  parts  of  the  dura  mater,  and  upon  the 
posterior  ethmoidal  cells,  where  it  anastomoses  upon  the  Schneide- 
rian membrane,  with  branches  from  the  internal  maxillary. 

5.  Arterise  Musculares.  Of  these  there  are  two;  one  of  them,  the 
inferior,  sends  branches  to  the  rectus  internus,  rectus  inferior,  and 
obliquus  inferior  oculi ; also  to  the  lachrymal  sac,  and  to  the  parts 
about  the  bottom  of  the  orbit.  It  occasionally  detaches  some  of 
the  ciliary  arteries.  The  superior  muscular  branch  is  also  called  the 
Supra  Orbitar.  It  supplies  the  muscles  of  the  superior  part  of  the 
orbit,  and  then  issuing  through  the  supra  orbitary  foramen,  it  is  spent 
in  arterioles,  upon  the  os  frontis  and  its  periosteum,  and  upon  the 
orbicularis  oculi,  corrugator  supercilii,  and  occipito-frontalis.  It 
anastomoses  there  with  other  branches  of  the  ophthalmic,  and  with 
the  temporal  artery. 

It  is  usual  for  the  anterior  ciliary  arteries  to  come  from  the  mus-= 
cular  branches. 

• 

The  Ophthalmic  Artery,  after  having  detached  all  the  aforesaid 
branches,  is  much  diminished  in  volume,  and,  advancing  along  the 
internal  part  of  the  orbit,  its  next  branch  is — 

6.  The  Arteria  Ethmoidea  Anterior,  which  dips,  into  the  anterior 
internal  orbitary  foramen,  and  is  divided  into  small  branches,  some 
of  which  are  spent  upon  the  adjacent  portion  of  the  dura  mater, 
others  upon  the  frontal  sinus  and  the  anterior  ethmoidal  cells. 
Some  of  these  branches  penetrate  from  the  cranium  through  the 
cribriform  plate  into  the  nose,  and,  ramifying  upon  the  Schneiderian 
membrane,  anastomose  with  the  internal  maxillary. 

7.  The  Arteriae  Palpebrales  are  two  in  number ; they  come  some-. 

38* 


442 


NERVOUS  SYSTEM. 


times  from  a common  trunk,  and  on  other  occasions  arise  separately. 
One  is  the  Superior,  and  the  other  the  Inferior.  The  latter  arises 
first,  and  is  distributed  to  the  conjunctiva,  the  caruncula  lachrymalis, 
lachrymal  sac ; and  finishes  by  many  small  branches  to  the  lower 
eyelid,  that  anastomose  with  the  infra-orbitar  artery,  so  as  to  form 
the  lower  tarsal  arch.  It  also  anastomoses  with  the  lachrymal  artery 
by  its  extreme  branches. 

The  Superior  Palpebral  Artery  also  distributes  branches  to  the 
conjunctiva,  sac,  and  caruncle  ; it  then  emerges  above  the  inner 
palpebral  ligament,  around  the  margin  of  the  superior  eyelid,  and 
forms,  along  with  the  lachrymal  and  the  supra  orbitar  artery,  the 
superior  tarsal  arch,  which  distributes  small  branches,  in  great 
profusion,  to  the  orbicularis  muscle,  and  to  the  structure  generally, 
of  this  lid.  It  anastomoses,  externally,  with  the  lower  palpebral 
artery. 

8.  The  Arteria  Nasalis  is  sometimes  a well  marked  continuation 
of  the  ophthalmic.  It  passes  out  of  the  orbit  at  its  internal  canthus, 
above  the  internal  palpebral  ligament,  and  anastomoses  at  the  root 
of  the  nose  with  the  facial  artery.  It  is  distributed  to  the  side  of  the 
nose,  and  to  the  lower  part  of  the  forehead.  Its  chief  contribution 
to  the  eyelids  is  at  the  internal  end  of  the  orbicularis,  where  it  anas- 
tomoses with  the  palpebral  arteries. 

9.  The  Arteria  Frontalis  passes  out  of  the  orbit  near  the  supra 
orbitary  foramen.  It  is  quickly  divided  into  branches,  which  go 
to  the  orbicularis,  the  occipito-frontalis  and  corrugator  muscles,  and 
to  the  frontal  sinus. 

Of  the  Veins  of  the  Orbit. 

The  blood  distributed  to  the  eye-ball  and  to  its  auxiliary  parts,  has 
two  routes  for  returning  to  the  heart,  one  through  the  cavernous 
sinus,  and  the  other  by  the  superficial  veins  of  the  face.  As  a gene- 
ral rule,  all  the  branches  of  the  ophthalmic  artery  which  reach  the 
eyelids,  or  become  otherwise  superficial,  return  their  blood  by  the 
latter  route ; and  those  whose  distribution  is  to  the  ball  of  the  eye 
and  to  the  parts  deeply  seated  in  the  orbit,  return  their  blood  by  the 


sinus. 


THE  EYE. 


443 


When  the  veins  are  well  injected,  a very  considerable  number  is 
manifested  in  both  eyelids.  They  form  a handsome  net-work,  the 
meshes  of  which  are  small  and  numerous,  and  commence  by  small 
roots  at  the  margin  of  the  eyelids.  The  vessels  of  this  net-work 
becoming,  successively,  larger  from  the  centre  to  the  circumference 
of  the  orbicularis  muscle,  cover  the  whole  surface  of  the  latter,  and 
from  the  thinness  of  the  skin  are  readily  seen  beneath  it.  The  veins 
of  the  lower  eye-lid  are  discharged  into  the  facial  vein,  where  it 
borders  on  the  orbicularis  ; and  the  veins  of  the  upper  lid,  being  bor- 
dered along  the  superior  margin  of  the  orbicularis  by  a horizontal 
branch  of  the  temporal  vein,  discharge  themselves  into  it. 

The  Ophthalmic  Vein  ( Sinus  Ophthalmicus ) is  the  large  trunk 
within  the  orbit  which  receives,  successively,  the  remaining  blood 
of  the  eye,  and  passing  along  the  internal  parts  of  the  orbit,  crosses 
over  the  optic  nerve,  and  penetrates  through  the  optic  foramen  into 
the  cavity  of  the  cranium,  where  it  terminates  in  the  cavernous 
sinus.  It  may  be  considered  as  commencing  by  an  anastomosis 
with  the  facial  vein  at  the  internal  canthus ; it  then  receives  the  fol- 
lowing branches  : — 

1.  The  nasal,  which  arises  from  the  parts  about  the  internal 
canthus  of  the  eye. 

2.  The  anterior  ethmoidal,  which  comes  from  the  nose  and  frontal 
sinus. 

3.  Branches  from  the  recti  and  obliqui  muscles. 

4.  The  lachrymal  vein,  from  the  lachrymal  gland  and  levator  pal- 
pebrse  muscle. 

5.  Posterior  ethmoidal  vein,  from  the  nose. 

6.  The  ciliary  veins,  or  those  of  the  choroid  coat,  which  are  very 
numerous. 

7.  The  central  vein  of  the  retina,  which  is  collected  from  three  or 
four  principal  branches,  and  follows  the  course  of  the  artery  of  the 
same  name,  through  the  cribriform  part  of  the  sclerotic  coat,  and 
through  the  centre  of  the  optic  nerve.  The  trunks  of  this  vein  anas- 
tomose, at  the  anterior  margin  of  the  retina,  with  those  of  the  Ciliary 
Body. 

There  are,  of  course,  frequent  anastomoses  between  the  veins  of 
the  eyelids  and  the  primitive  branches  of  the  ophthalmic  vein. 


444 


NERVOUS  SYSTEM. 


SECT.  II. — OF  THE  BALL  OF  THE  EYE.* 

The  Eye-ball  ( Bulbus  Oculi)  is  situated  within  the  anterior  half 
of  the  orbit,  from  which  it  is  kept  separated  by  its  auxiliary  parts, 
and  by  a large  quantity  of  adipose  matter  which  fills  up  their  inter- 
stices. It  is  very  nearly  spherical,  but  not  so  much  so  as  to  pre- 
vent its  antero-posterior  diameter,  which  is  about  an  inch  long,  from 
exceeding  in  measurement  every  other.  Such,  at  least,  is  the  general 
opinion  of  anatomists,  but  from  experiments,  made  by  distending  the 
eye  with  mercury,  I have  been  induced  to  doubt  its  correctness,  and 
especially  in  the  African ; for,  in  the  latter,  I have  uniformly  found 
the  transverse  diameter  to  exceed  the  antero-posterior  by  a line  or 
more.  The  Eye-ball  is  also  somewhat  flattened  at  the  insertion  of 
each  of  the  straight  muscles. 

It  is  formed  by  a series  of  concentric  tunics,  one  investing  the 
other,  and  by  humours  contained  within  those  tunics.  Of  the 
former,  the  Sclerotica  and  the  Cornea  are  external,  the  Choroidea 
and  the  Iris  next,  and  the  Retina  is  internal.  Of  the  Humours,  the 
Vitreous  is,  by  far,  the  most  abundant,  and  constitutes  a principal 
part  of  the  eye-ball ; the  Crystalline  Humour  is  in  front  of  the  vi- 
treous ; and  the  Aqueous  is  placed  between  the  crystalline  and  the 
cornea. 

Tunics , or  Membranes  of  the  Eye-ball. 

The  Sclerotic  Coat  ( Tunica  Sclerotica , Albuginea ) forms  about 
five-sixths  of  the  exterior  investment  of  the  eye-ball,  the  remaining 
sixth  of  which  is  obtained  from  the  cornea.  At  its  posterior  part  it 
is  joined  by  the  optic  nerve:  this  junction  does  not  occur  precisely 
at  its  axis  or  centre,  but  at  the  inner  side  of  it.  When  the  optic 
nerve  is  detached  at  this  junction,  a small  round  hole  is  perceptible 
in  the  sclerotica,  or,  rather,  it  is  more  frequently  perceived  as  a thin 
cribriform  lamella,  through  the  holes  of  which  the  pulpy  part  of  the 
optic  nerve  passes,  so  as  to  get  within  the  eye.  This  cribriform 
lamella,  or  the  appearance  of  it,  is  no  doubt  produced  artificially  by 
the  nerve  being  commonly  cut  through  very  near  the  eye ; and,  as 


Anat.  Atlas,  Figs.  5G5  to  568,  inclusive. 


THE  BALL  OF  THE  EYE. 


445 


Mr.  Jacobs,  of  Dublin,  very  properly  suggests,  should  be  con- 
sidered as  the  most  anterior  termination,  or  the  point  of  the  optic 
nerve  instead  of  as  a portion  of  the  sclerotica.  The  neurileme  of 
the  optic  nerve,  is  so  arranged,  that  small  round  longitudinal  canals 
are  left,  which  contain  the  nervous  matter;  from  this  cause  it  hap- 
pens that  a thin  section  of  the  optic  nerve  in  any  part  of  its  course 
in  the  orbit,  will,  if  held  up  to  the  light,  manifest  the  same  cribri- 
form arrangement  with  the  part  alluded  to.  This  part  of  the  struc- 
ture of  the  optic  nerve  will  be  readily  understood  by  the  American 
student,  in  comparing  it  with  the  pith  of  the  Indian  corn-stalk, 
which,  being  traversed  longitudinally,  by  many  fibres,  upon  the 
drawing  of  them  out,  an  equal  number  of  longitudinal  canals  is  left 
in  their  places. 

At  its  fore  part,  the  edge  of  the  sclerotica  is  bevelled  all  around 
for  its  junction  with  the  cornea;  and  though  nearly  circular,  is  not 
completely  so,  from  its  horizontal  diameter  being  somewhat  greater 
than  any  other.  There  are  several  orifices  of  inconsiderable  size 
scattered  over  the  sclerotica,  some  of  which  are  oblique  and  others 
direct:  they  transmit  the  blood  vessels  and  nerves.  The  Sclerotica 
is  nearly  a line  in  thickness  at  its  back  part,  from  which  it  gradually 
becomes  reduced  to  half  thatthiekness  in  front,  where  it  is  strengthened 
by  the  tendinous  insertions  of  the  recti  muscles.  Its  internal  surface 
is  smooth  and  somewhat  shining,  being  loosely  attached  to  the 
cellular  substance  intervening  between  it  and  the  choroid  coat ; but 
the  external  surface  is  rough,  and  more  obviously  fibrous,  and  is 
attached  somewhat  strongly  to  all  the  adjoining  parts,  by  the  cellular 
substance  latterly  called  the  sclerotic  fascia. 

The  sclerotica  is  of  a white  colour,  and  consists  of  a single  layer, 
whose  structure  is  essentially  fibrous.  The  fibres  are  very  closely 
compacted,  and  compose  an  intertexture  which  cannotbe  unravelled. 
It  is  so  firmly  united  to  the  dura  mater  covering  of  the  optic  nerve, 
that  many  anatomists,  notwithstanding  its  greater  thickness,  are  dis- 
posed to  speak  of  it  as  a continuation  of  the  same.  Its  strength  and 
its  want  of  elasticity  suit  it  remarkably  to  maintain  the  form  of  the 
eye,  and  to  resist  injuries.  Out  of  the  many  blood  vessels  that 
penetrate  it,  but  few  ramify  in  its  structure. 

The  existence  of  nerves  in  the  cornea  is  by  no  means  evident. 
Some  anatomists,  as  Schlemm,  claim  to  have  traced  branches  of  the 
ciliary  nerves  into  it  ;*  but  this  is  denied  by  Arnold. 

* Lawrence  on  Eye,  p.  21.  London,  1841. 


446 


NERVOUS  SYSTEM. 


The  tunica  arachnoidea  follows  the  course  of  the  optic  nerve, 
within  its  coat  of  dura  mater,  and  forms,  in  the  eye,  just  around  the 
cribriform  plate,  or  foramen  of  the  sclerotica,  a circular  pad : it  is 
then  reflected  on  the  internal  face  of  the  sclerotica,  as  far  as  its  ante- 
rior edge.  It  is  this  which  causes  the  internal  face  of  the  sclerotica 
to  be  smooth  and  shining,  and  thereby  to  correspond  with  that  of 
the  dura  mater.*  This  circumstance  is  more  readily  proved  in  a 
very  young  eye,  than  in  the  adult  one. 

The  Cornea,  ( Cornea ) as  mentioned,  fills  up  the  aperture  at  the 
fore  part  of  the  sclerotica,  and,  of  course,  has  the  same  diameters, 
with  this  opening ; measuring  thereby  more  transversely  than  in  any 
other  direction.  It  is  a segment  of  a smaller  sphere  than  the  scle- 
rotica, and  is,  consequently,  more  convex  than  it.  Its  thickness  is 
uniform,  and  commonly  exceeds  that  of  the  sclerotica  at  the  fore  part 
of  the  latter. 

Its  circumference  adheres  very  closely  to  the  sclerotica,  and  pre- 
sents a bevelled  or  oblique  edge,  which  is  inserted  into  the  corres- 
ponding bevel  of  the  sclerotica,  so  that  the  latter  includes  the  former. 
The  closeness  of  this  junction  induced  the  older  anatomists  to  con- 
sider these  membranes  as  one  and  the  same,  notwithstanding  their 
obvious  difference  of  sensible  properties.  Their  adhesion  yields 
to  protracted  maceration.  The  cornea  is  covered  in  front  by  a con- 
tinuation of  the  tunica  conjunctiva,  which  unites  the  eye-ball  to  the 
eye-lids.  This  may  be  proved  by  dissection,  by  maceration,  and 
by  its  coming  off  entirely,  along  with  the  epidermis  of  animals  that  are 
subject  to  this  process  of  moulting;  as  the  locust,  snakes,  and  others. 
On  its  posterior  face  it  is  covered  by  the  membrane  of  the  aqueous 
humour;  which  may  be  rendered  evident  by  steeping  it  in  spirits  of 
wine,  whereby  the  latter  membrane  is  made  more  hard,  and  may  be 
thus  torn  off.  This  capsule  of  the  aqueous  humour  differs  decidedly 
from  the  cornea  in  not  being  made  so  opaque  by  the  immersion  in 
spirits  of  wine,  we  may  hence  infer  the  defect  of  an  albuminous  con- 
stituent in  it. 

The  cornea  in  a natural  state,  is  perfectly  transparent,  and  readily 
transmits  the  rays  of  light.  It  is  of  a fibrous  structure,  easily  mani- 
fested by  soaking  it  in  alcohol,  and  consists  of  an  indefinite  number 

* J.  F.  Meckel.  Zinn  supposed  this  surface  to  be  derived  from  the  pia  mater. 


BALL  OF  THE  EYE. 


447 


of  laminae,  which  are  placed  one  against  the  other  like  the  leaves  of 
a book ; they  are  united  by  a delicate  transparent  cellular  substance 
which  permits  the  laminae  to  slide  upon  each  other.  These  laminae 
are  kept  moist  and  pellucid  by  an  interstitial  secretion  of  a fluid 
equally  pellucid  with  themselves ; the  abundance  of  which  in  health 
gives  to  the  eye  its  brilliancy,  and  the  deficiency  of  it  in  illness  and 
in  death  causes  the  eye  to  look  dim  and  somewhat  opake.  Its 
evaporation,  which  no  doubt  is  continually  occurring,  is  as  constant- 
ly supplied  by  a fresh  and  abundant  secretion.  The  motion  of  the 
eye-lids  sweeps  the  residuum,  after  the  evaporation  of  its  watery 
particles,  from  the  surface  of  the  cornea  : without  this  process,  the 
residuum  appears  as  a thin  layer  or  film  of  albuminous  matter  spread 
over  the  cornea,  when  the  eye  is  kept  open  without  winking  for  a 
considerable  time.  The  cornea  tried  by  the  microscope,  has  a close 
resemblance  to  cell-cartilage  or  fibro-cartilage,  approximating,  how- 
ever, more  the  former,  but  the  cells  are  not  in  the  same  abundance. 
They  have  around  them  an  investment  of  bright  fibres,  loosely  con- 
nected together,  and  forming  a plexus  resembling  areolar  or  cellular 
tissue. 


Fig.  40. 


The  cornea  has  not  at  first 
sight  the  strong  unyielding  struc- 
ture with  the  sclerotica,  yet  the 
application  of  mechanical  force 
to  the  eye-ball  shows  that  it  is 
stronger.  Neither  has  it  ves- 
sels, conveying  red  blood  natu- 
rally, yet,  in  a state  of  inflamma- 
tion, its  capillaries  dilate  so  as 
to  admit  red  blood,  and  depo- 
site  coagulating  lymph  between 
its  layers.  It  is  common  for 
anatomists  to  attribute  a want  of 
sensibility  to  it  in  a natural  state : 
as  a general  rule  this  is  falla- 
cious ; for  many  persons,  where  the  eyes  are  not  inflamed,  suffer 
extremely  from  its  being  cut  in  cataract,  and  sometimes  faint  from  the 
pain ; while  others  are  truly  unconscious  of  the  incisions  made  through 
it.  For  this  opinion,  I have  had  a full  assurance  from  repeated  ob- 
servations on  the  practice  of  Dr.  Physick,  as  well  as  from  instances 
in  my  own  hands. 


Horny  Epidermis,  on  conjunctiva  as  it 
covers  the  cornea ; a insulated  scales  ; b, 
tesselated  simple  lamina  of  scales,  and 
lower  down  is  seen  a double  lamina  of  the 


448 


NERVOUS  SYSTEM. 


The  difference  of  actual  texture  between  the  cornea  and  the 
sclerotica  is  very  inconsiderable ; we  are  commonly  misled  by  the 
transparency  of  the  cornea,  but  if  the  albumen  in  it  be  coagulated 
by  alcohol  or  neutral  salts,  the  filaments  of  the  two  are  identical  in 
appearance.  Dr.  Arnold  considers  both  to  be  formed  of  cellular 
substance  permeated  by  an  extremely  fine  close  set  of  lymphatics,* 
an  idea  originating  with  Mascagni  and  applied  by  him  to  every  tissue 
of  the  body. 

If  a minute  injection  be  successfully  thrown  into  the  conjunctival 
blood  vessels  of  an  infant,  a beautiful  vascular  corona  is  formed  at 

the  anterior  margin  of  the  sclerotica. 
Professor  Roemer,  of  Vienna,  con- 
siders it  to  consist  of  two  layers,  a 
superficial  derived  from  the  lachrymal 
and  palpebral,  and  a deeper  one,  from 
the  muscular  and  ciliary  arteries. 
From  this  corona  the  surface  of  the 
cornea  is  supplied,  and  also  its  sub- 
stance by  converging  branches.  The 
superficial  vessels  are  prolonged  natu- 
rally one-eighth  or  half  a line  beyond 
the  margin  of  the  cornea  and  return 
as  veins.  The  deep  do  not  pass  into 
the  cornea,  but  end  at  its  margin, 
in  dilatations  which  return  as  veins. 
When  blood  vessels  are  formed  in  the 
cornea  beyond  these  limits  they  are 
as  in  the  case  of  an  apparently  vas- 
cular cartilage,  the  attendant  of  a new 
tissue  in  the  cornea,  the  product  of 
inflammation. 

The  Choroid  Coatf  ( Tunica  Choroidea  Vasculosa ,)  is  placed  im- 
mediately within  the  circumference  of  the  sclerotica,  and  is  of  equal 
extent.  At  its  posterior  part  it  furnishes,  for  the  passage  of  the  optic 
nerve,  a single  circular  opening,  the  margin  of  which  is  somewhat 
thickened,  and  perfectly  distinct  from  the  pia  mater  investment  of 
the  nerve,  from  which  some  anatomists  have  desired  to  trace  this 


Fig.  41. 


Blond  Vessels  of  the  Cornea. 
a.  Superficial  vessels  belonging  to 
the  conjunctival  layers,  and  con- 
tinued beyond  the  margin  of  the 
Cornea ; b.  Vessels  of  the  Sclerotic 
running  their  course  and  returning, 
at  the  margin  of  the  Cornea. 


Lawrence  on  Eye,  p.  14. 


t Anat.  Atlas,  Figs.  569,  570,  571,  581. 


449 


THE  BALL  OF  THE  EYE; 

coat.  The  anterior  opening  of  the  choroid  is  bounded  by  the  ciliary 
ligament  and  by  the  iris.  On  its  outer  side  may  be  seen  an  abund- 
ance of  loose  flocculent  cellular  substance  which  joins  it  to  the  scle- 
rotica. Internally,  it  is  spread  over  the  retina,  but  does  not  adhere 
to  it. 

The  choroid  coat  is  closely  fastened,  at  its  anterior  margin,  to  the 
corresponding  part  of  the  sclerotica,  by  a ring  which  surrounds  it, 
of  a short  compact  cellular  tissue.  This  ring,  called  the  Ciliary 
Ligament,  ( Ligamentum  Ciliare , Orbiculus  Ciliaris,)  is  from  a line 
to  two  lines  in  breadth,  and  may  be  readily  distinguished  by  its 
whiteness,  contrasted  with  the  dark  colour  of  the  choroid.  It  is 
intimately  united  to  the  latter,  and  seems  to  form  a part  of  its  struc- 
ture, whereby  it  is  caused  to  detach  itself  entirely  from  the  sclerotica, 
and  to  adhere,  by  preference,  to  the  choroid  when  these  two  mem- 
branes are  separated.*  The  iris  is  set  in  the  front  margin  of  the 
ciliary  ligament,  so  that  the  sclerotica  and  the  cornea  may  be  peeled 
from  the  choroidea  and  iris,  without  impairing  the  continuity  of  the 
two  latter.  Just  beyond  the  junction  of  the  two  last,  the  ligament 
presents  a small  ridge  or  elevation  all  around,  which  is  fitted  into  a 
corresponding  fossa  at  the  circumference  of  the  posterior  face  of  the 
cornea. 

The  internal  face  of  the  choroid  coat,  as  well  as  its  anterior  mar- 
gin, undergoes  a very  remarkable  change  from  the  general  plan  of 
this  tunic,  by  forming  what  is  called  the  Ciliary  Body,  ( Corpus 
Ciliare , Corona  Ciliaris.)  In  order  to  see  this  in  the  most  favour- 
able manner,  the  eye  should  be  laid  on  the  cornea,  and  its  posterior 
half  cut  away.  It  will  then  be  evident,  that  just  behind  the  iris, 
and  within  the  circumference  of  the  ciliary  ligament,  the  internal 
face  of  the  choroid  coat  forms  a considerable  number  of  radiated 
folds  or  little  ridges,  which  converge  from  behind  forwards  and  in- 
wards. These  folds  commence  by  striae,  almost  imperceptible  to 
the  naked  eye,  which  are  in  contact  with  the  fore  part  of  the  vitreous 
humour,  and  with  the  canal  of  Petit ; and  thereby  not  only  impress 
the  neighbouring  portion  of  the  tunica  hyaloidea  with  their  shape, 
but  even  leave  upon  it  the  black  pigment  with  which  they  themselves 

* Fontana  asserted,  from  seeing  it  in  an  ox,  that  a circular  canal  was  to  be  found, 
in  this  ligament;  many  examiners  have  failed  in  finding  it,  and  its  existence  is  de- 
nied by  Arnold,  who  states  it  to  be  a venous  tube  in  the  thickness  of  the  sclerotica 
far  receiving  the  veins  of  the  Iris,  and  called  by  him  Circulus  Venosus  Iridis.  It 
cannot  be  injected  except  from  the  arteries. 

Vol.  II.— 39 


450 


NERVOUS  SYSTEM. 


are  covered.  These  folds,  when  they  get  near  the  circumference  of 
the  iris,  coalesce  one  with  another,  and  terminate  in  a considerable 
number  (from  fifty  to  sixty,  according  to  Soemmering,)  of  processes, 

( Processus  Ciliares ,)  the  central  extremities  of  which  are  loose,  and 
tloat  in  the  aqueous  humour.  Some  of  these  processes  are  longer 
than  others.  As  a whole  the  ciliary  processes  constitute  a ring  of 
radiating  filaments,  which  are  a line  or  more  in  length,  placed 
along  side  of,  and  in  contact  with,  one  another ; the  external  peri- 
phery of  the  ring  adheres  to  the  ciliary  ligament,  and  through  it  to 
the  greater  circumference  of  the  iris,  so  that  the  ring  appears,  but 
fallaciously,  to  be  continuous  with  the  iris.  In  certain  animals'  as 
the  sheep,  the  radiated  appearance  of  the  iris,  on  its  posterior  face, 
favours  this  notion  still  more.  The  internal  periphery  of  the  ring 
presents  the  central  ends  of  the  filaments  detached  from  one  another, 
and  of  a downy  appearance.  With  the  handle  of  a knife  they  may  be 
readily  pushed  backwards  and  forwards.  Generally  speaking,  the 
ciliary  processes  are  so  much  concealed  by  the  iris,  that  they  cannot 
be  seen  in  the  living  body  through  the  cornea : in  cases,  however, 
of  extreme  dilatation  of  the  pupil  by  narcotic  applications,  their  cen- 
tral extremities  are  brought  into  view. 

The  choroid  coat  always  appears,  when  uninjected,  of  a very 
dark  brown,  or  black  colour,  arising  from  a black  paint  ( Pigmen - 
turn  JYigrum ) being  very  thickly  spread  over  the  whole  of  that  sur- 
face of  it  which  is  adjacent  to  the  retina,  and  being  also  diffused 
through  its  thickness.  This  paint  is  more  abundant  near  the  iris 
than  posteriorly,  being  laid  on  there  in  flakes,  in  the  intervals  be- 
tween the  ciliary  striae,  and  tinging  also  the  ciliary  processes.  It 
may  be  removed  in  a considerable  degree,  indeed  almost  entirely, 
by  maceration,  or  by  careful  washing  with  a camel’s-hair  pencil. 
It  is  supposed  to  be  an  exhalation  from  the  vessels.  This  pigment 
of  the  choroid  coat  is  contained  in  very  fine  cells,  of  a hexagonal 
shape,  and  making  a continuous  membrane  from  their  abundance. 
Its  particular  colour  is  of  a most  durable  kind.  According  to  the 
observations  of  Bichat,  the  long-continued  action  of  light  upon  it, 
when  this  pigment  is  transferred  from  the  choroid  to  a piece  of 
paper,  does  not  affect  it ; neither  is  it  changed  by  being  submitted 
to  very  strong  chemical  agents,  as  sulphuric,  muriatic,  or  nitric 
acid,  alcohol,  or  caustic  potash.  This  degree  of  indestructibility 
of  colour  is  an  invaluable  property,  and  almost  singular ; for  it  is 
well  known  to  the  keepers  of  medicinal  articles,  that  the  colours 


THE  BALL  OF  THE  EYE. 


451 


PiOTpira 


of  them  all  yield  to  the  continued  influence  of  light,  and  that  they 
also  become  weaker  by  the  same  cause.  This  indestructibility  by- 
light,  continues  so  long  as  the  dry  state  is  preserved.  A human 
choroid  kept  in  alcohol  and  exposed  to  light  I have  generally 
found  to  turn  white  in  a series  of  years;  in  the  sheep  and  bullock 
it  is  not  so.  ' 

In  regard  to  structure,  the  Flir- 42- 

choroid  coat  is  thin,  soft  and 
easily  lacerated  : when  cleared 
of  its  pigment  by  maceration, 
it  is  semi-transparent,  and  is 
then  seen  evidently  to  consist 
of  but  one  lamina ; unless  we 
may  be  disposed  to  consider 
as  a second  one  the  pigment, 
naturally  on  its  internal  face. 

It  has  no  appearance  of  fibres 
in  its  composition,  but,  when 
injected,  seems  to  consist  al- 
most wholly  of  arteries  and  of 
veins. 

The  arteries  are  branches  of 
the  ophthalmic,  and  are  called 
ciliary.  There  are  Two  Long  Ciliary  Arteries,  which  penetrate 
the  sclerotic  coat  not  far  from  the  optic  nerve,  and  pass,  one  of 
them,  on  the  external  and  superior  part  of  the  choroidea,  and  the 
other  on  its  inferior  and  nasal  side,  to  the  front  of  the  eye.  In  this 
course  they  do  not  send  off'  any  branches  of  consequence  till  they 
reach  the  iris,  upon  which  they  are  distributed.  The  Short  Ciliary 
Arteries  are  much  more  numerous  than  the  others,  and  also  smaller  ; 
their  number  sometimes  amounts  to  twenty  ; the  most  of  them 
penetrate  the  sclerotica  from  behind,  near  the  optic  nerve  also.* 
They  quickly  divide  into  a great  number  of  branches,  which  de- 
part at  very  acute  angles,  and  have  frequent  anastomoses  with  one 
another.  These  branches  run  forwards,  nearly  parallel,  and  at 
the  fore  part  of  the  choroides,  form  a very  intricate  intertexture, 
which  is  continued  upon  the  ciliary  processes,  and  communicates 
with  the  vessels  of  the  iris.f 


Section  of  Choroidea  of  the  the  Ox,  mag 
nified  fifty-six  diameters,  a,  a , a.  Veins 
covered  by  a single  layer  of  pigment  cells- 
At  b,  b,  the  pigment  is  pointed  and  reticu. 
lated.  c,  c,  Intervals  of  veins  thickly  co- 
vered with  the  pigment  cells.  After 
Gerber. 


* Soemmering,  leones  Oculi  Humani. 


leones  Oculi  Humani. 


452 


NERVOUS  SYSTEM. 


The  veins  of  the  choroid  coat  are  also  extremely  abundant. 
They  run  from  before  backwards,  and  the  branches  which  concur 
to  form  them,  being  adjacent  with,  and  parallel  to  each  other,  for 
the  most  part,  form  large  curves,  the  convexity  of  which  is  for- 
wards ; they,  moreover,  anastomose  freely,  and  thereby  produce  a 
vascular  sort  of  net-work,  filling  up  the  concavity  of  some  of  the 
curves.  These  veins,  called  the  Vasa  Vorticosa,  are  nearer  the 
external  surface  of  the  choroides  than  the  arteries,  and  are  assem- 
bled into  twelve  or  fourteen  trunks,  which,  engaging  in  the  sclero- 
tica, near  its  middle,  run  for  some  distance  in  its  substance,  and 
then,  by  their  junction,  are  reduced  to  four  or  five  in  number.  The 
latter,  disengaging  themselves  from  the  eye,  join,  subsequently,  the 
ophthalmic  vein. 

In  addition  to  the  veins  mentioned,  the  long  ciliary  arteries  have 
their  veme  comites,  which  take  a course  parallel  to  and  adjoining 
them.  These  veins  do  not  observe  the  vortical  arrangement  of  the 
others  ; they  bring  back  the  blood  of  the  iris,  and  terminate  in  the 
larger  trunks  of  the  others. 

The  choroidea  has  been  most  cautiously  explored  by  the  cele- 
brated Soemmering,  whose  observations  have  tended  very  much 
to  determine  the  opinions  of  anatomists  concerning  many  parts  of 
the  eye.  A curious  remark  of  his  is,  that  “the  human  eye  may  be 
distinguished  from  that  of  animals  by  a form  of  this  vascular  net 
work,  entirely  peculiar ; for  example,  in  the  eye  of  the  ape,  its  vas- 
cular tissue  differs  not  only  from  that  of  the  human  subject,  but 
also  from  that  of  the  dog,  and  still  more  evidently  from  that  of  the 
calf.  From  which  cause,  it  would  be  as  easy  to  distinguish  with 
a microscope,  the  choroides,  well  injected,  of  different  animals, 
even  a piece  of  only  the  forty-eighth  part  of  an  inch  in  extent,  as 
it  is  easy  to  distinguish  a poplar  stripped  of  its  leaves  from  an  oak, 
a pear  tree,  an  apple  tree  or  any  other  tree,  by  the  arrangement  of 
its  trunk  and  branches.” 

The  choroides,  on  its  internal  face,  is  not  smooth,  but  velvety, 
which  become  still  more  conspicuous  when  the  eye  is  finely  in- 
jected and  examined  with  a microscope.  Meckel  considers  the 
appearance  to  depend  upon  its  very  fine  tissue  of  vessels.  This 
surface  is  called  Tapetum.*  In  the  bullock,  and  some  other  ani- 
mals, at  a particular  part,  it  presents  a shining,  silvery  appearance, 
and  may  be  tom  off’  from  the  external  surface.  Ruysch  attributed 


* From  tapes,  tapestry. 


THE  BALL  OF  THE  EYE. 


453 


two  laminse  to  the  choroid  membrane  in  the  human  subject,  the  in- 
ternal of  which  was  called  after  his  name,  but  the  distinction  is 
now  generally  abandoned. 

The  Iris,  (Iris,)*  is  a circular  plane  placed  at  the  front  of  the 
choroides,  and  having,  in  its  centre,  a round  opening  called  the 
pupil  ( pupilla .)  Its  external  circumference  as  stated  is  attached  to 
the  ciliary  ligament,  and  by  it  to  the  choroid  coat,  and  is  exactly 
at  the  junction  of  the  cornea  with  the  sclerotica.  Professor  Soem- 
mering has  bestowed  much  attention  in  ascertaining  whether  this 
membrane  is  perfectly  flat  or  somewhat  convex  in  front,  and  by  re- 
peated observations,  carefully  made,  has  assured  himself  that  it  is 
flat.f  My  own  observations  and  preparations  have  induced  me  to 
believe  that  in  many  cases  it  will  be  found  slightly  convex  in  front, 
as  Petit  asserted  more  than  a century  ago.  In  a moderate  state  of 
dilatation,  its  nasal  or  internal  border  is  somewhat  narrower  than 
its  external  or  temporal.  With  the  exception  of  its  external  cir- 
cumference, every  part  of  the  iris  is  devoid  of  any  attachment;  by 
which  arrangement  it  moves  freely  in  the  aqueous  humour,  so  as  to 
contract  or  dilate  the  pupil,  according  to  the  quantity  of  light  ad- 
mitted upon  the  eye. 

The  iris,  with  the  exception  of  its  central  or  pupillary  circum- 
ference, where  it  is  thinner  than  elsewhere,  is  much  thicker  than 
the  choroid  coat.  The  posterior  face  of  the  iris,  sometimes  called 
Uvea,  is  covered  in  great  abundance  with  pigmentum  nigrum. 
When  this  is  removed  by  maceration,  which  may  be  readily  done, 
the  membrane  becomes  semi-transparent.  Its  anterior  surface  is 
the  seat  of  the  colour,  which  characterizes  every  individual’s  eyes. 
There  are  but  two  of  these  colours,  light  blue  and  orange,  the 
predominance  of  one  or  the  other  of  which,  assisted  by  the  dark 
ground  on  the  back  of  the  iris,  gives  the  cast  of  hue  to  the  eye. 
The  front  surface,  when  examined  on  the  living  eye,  with  the  mi- 
croscope, is  seen  to  be  downy  or  flocculent,  and  is  traversed  by- 
filaments,  forming  an  intertexture,  some  of  which  are  circular, 
others  oblique  ; and  others  radiated.  This  arrangement  is  remark- 
ably distinct  in  the  eye  of  the  seal. 

The  power  which  the  iris  has  of  dilating  the  pupil  when  there 
is  but  little  light,  and  of  contracting  it  when  there  is  much,  has 
induced  many  anatomists  to  think  that  it  is  formed  of  muscular 

* Anat.  Atlas,  582,  583,  f leones  Oculi  Humani, 

39* 


454 


NERVOUS  SYSTEM. 


radiated  fibres,  which  by  their  contraction  produce  the  first  mo- 
tion, and  of  circular  ones  which  produce  the  last.  Among  these 
anatomists  may  be  mentioned,  Ruysch,  Morgagni,  Zinn,  Sabatier. 
Ruysch  asserted  that  the  radiated  fibres  extended  from  the  greater 
circumference  of  the  iris  to  the  pupil,  and  were  fixed  there  by  very 
delicate  tendons.  The  late  Doctor  Monro,  of  Edinburgh,  has  de- 
scribed particularly  the  circular  fibres,  and  a preparation  of  the 
bullock’s  eye  which  belonged  to  him  is  still  exhibited  there,  where 
these  fibres  are  found  around  the  margin  of  the  pupil.  The  several 
fibres  can  only  be  seen  distinctly,  when  the  pigmentum  nigrum  is 
washed  away.  Demours  and  Meckel  deny  the  existence  of  the 
radiated  fibres.  The  late  distinguished  Professor  Wistar  taught 
that  the  contraction  of  the  pupil  was  produced  by  circular  fibres, 
and  the  dilatation  of  it  by  its  elasticity.  In  objection  to  this,  the 
late  Dr.  Physick  remarks,  that  as  elasticity  is  as  much  a property 
of  dead  as  of  living  matter;  in  death,  therefore,  we  should  always 
find  the  pupil  dilated  from  the  want  of  active  contraction  in  the 
circular  fibres  ; also,  in  cases  of  concussion  of  the  brain,  where 
there  is  a sudden  loss  of  sensibility  and  of  muscular  motion,  the 
pupil  should  be  invariably  dilated  ; but  the  fact  is,  that  the  pupil 
remains  just  in  the  same  state,  that  it  was  at  the  moment  of  the 
accident.  The  distinguished  anatomist,  Arnold,  has,  after  very 
careful  inquiry,  come  to  the  conclusion  that  the  Iris  is  formed 
of  numerous  blood  vessels,  of  many  nerves  and  of  cellular  sub- 
stance. The  point  of  the  muscularity  of  the  Iris  received  a 
strong  confirmation  from  the  observations  of  Mr.  Bauer  in  1822,* 
and  since  then  additional  observations  to  the  present  date,  with 
the  most  improved  microscopes,  have  added  to  the  evidence  so 
that  the  affair  may  be  considered  as  almost  incontrovertibly  settled. 
The  most  modern  observers  admit  as  former  ones  did,  two  orders 
of  fibres,  the  radiated  and  the  circular;  the  first  occupying  princi- 
pally the  front  of  the  iris  and  the  last  the  posterior  face.  These 
muscular  fibres  are  destitute  of  transverse  striae,  form  a plexus  by 
their  unions,  and  resemble  the  muscular  fibres  of  the  large  intestines. f 

Notwithstanding  the  extreme  sensibility  and  mobility  of  the  iris 
on  the  admission  of  light,  one  is  occasionally  astonished  to  find  it 
not  contracting  when  instruments  are  applied  to  it,  as  I have  had  an 

* Philos.  Trans. 

t For  the  opinions  of  Pappenheim,  Krause,  Valentin  and  others,  in  favour  of  this 
view,  see  Husehke  Traite  de  Splanch.,  p.  653.  Paris,  1815. 


THE  BALL  OF  THE  EYE. 


455 


opportunity  of  twice  observing,  upon  the  removal  of  a considerable 
portion  of  it,  in  making  an  artificial  pupil  for  opacity  of  the  cornea. 
In  these  cases,  upon  the  letting  out  of  the  aqueous  humour,  it  be- 
came quite  as  flaccid  as  we  are  accustomed  to  see  it  in  our  dissec- 
tions. The  same  remark  has  been  made  by  the  late  Sir  Charles 
Bell. 

The  Blo'od  Vessels*  of  the  lris  are  principally  branches  of  the  Long 
Ciliary,  which  have  been  alluded  to.  Each  of  the  two  Long  Ciliary 
Arteries  having  gained  the  greater  circumference  of  the  iris,  bifur- 
cates; the  bifurcation  runs  along  this  circumference,  meets,  and  joins 
with  the  corresponding  one  of  the  other  arterial  trunk.  From  the 
circle  thus  formed  there  proceed  radiated  branches,  that  run  towards 
the  pupil,  and  form  around  its  margin,  by  their  frequent  anastomoses, 
a fine  vascular  net-work.  The  radiated  branches  themselves  give  off 
collateral  branches,  which  supply  the  intermediate  spaces  of  the  iris. f 
The  veins  of  the  iris  are  also  numerous,  but  cannot  be  quite  so  dis- 
tinctly seen:  they  enter  into  the  long  ciliary  veins,  and  also  into  the 
vasa  vorticosa. 

The  Nerves  of  the  Iris  belong,  in  part,  also  to  the  choroid  coat, 
and  are  classed  under  the  term  Ciliary,  ( Nervi  Ciliares.)  They 
arise  from  the  ophthalmic  ganglion,  and  from  the  trunks  contributing 
thereto,  and  are  about  twenty  in  number.  They  penetrate  the  pos- 
terior part  of  the  sclerotica  obliquely,  and  then  run  forwards  between 
it  and  the  choroides.  Having  reached  the  posterior  part  of  the  ciliary 
ligament,  they  penetrate  it,  and  distribute  their  filaments  in  its  sub- 
stance, after  the  same  fashion  that  the  trigeminus  nerve  is  divided  in 
its  ganglion.  This  circumstance  has  given  occasion  to  Soemmering 
to  consider  the  ligament  as  a true  ganglion,  and  to  call  it  Annulus 
Gangliformis.  The  nerves  then  get  to  the  front  of  the  iris,  and  are 
there  distributed  as  white  radiating  filaments ; in  the  course  of  which 
may  be  observed  small  nodes,  supposed  by  Meckel  to  be  Gang- 
lions. 

The  trunks  of  the  ciliary  nerves  depart  from  the  common  form  of 
such  bodies,  by  being  flattened  instead  of  cylindrical : they  are  small, 
and  resemble  sewing  threads.  From  their  number,  the  iris  is  pro- 
bably more  abundantly  supplied  with  nerves  than  any  other  organ  of 
the  body. 

* Anat.  Atlas,  Fig.  576. 

t Soemmering,  leones  Oculi  Ilumani. 


456 


NERVOUS  SYSTEM. 


Interposed  between  the  choroides  and  the  retina,  is  a most  deli- 
cate serous  membrane,  which  was  discovered  by  Mr.  Jacobs,  now 
Professor  of  Anatomy  in  Trinity  College,  Dublin.  By  preparing 
the  retina  in  the  usual  way,  and  then  floating  the  eye  in  a saucer  of 
water,  this  membrane  may  be  turned  down  with  the  handle  of  a 
scalpel  from  the  optic  nerve  to  the  termination  of  the  retina.  It  is 
supposed  to  be  the  seat  of  the  ossifications  which  are  sometimes  met 
with  in  the  eye.  This  membrane  considered  by  some  as  in  fact  the 
external  lamina  of  the  retina  itself,  is  composed  of  corpuscles  set  in 
a perpendicular  direction*  like  the  pile  of  velvet.  These  corpuscles 
are  of  two  sizes,  great  and  small,  of  which  the  latter  are  more  nu- 
merous than  in  the  others. 

The  Retina  (Retina) f forms  the  deeper  coat  of  the  eye,  and  lines 
the  internal  face  of  the  choroides  almost  in  its  whole  extent.  The 
optic  nerve  having  passed  through  the  sclerotica  and  choroidea,  ter- 
minates on  their  inner  side  by  a bulb  or  button-like  end;  from  the 
circumference  of  which  the  retina  begins  to  expand,  and  may  be 
traced  satisfactorily  as  far  as  the  commencement  of  the  ciliary  plaits 
of  the  choroid  coat ; where  it  ceases  by  a straight  edge,  somewhat 
thickened.  Just  at  the  edge,  the  retina  adheres  to  the  vitreous 
humour,  and  is  supposed,  erroneously  by  some  anatomists,  as 
Bichat  and  Monro,  to  be  continued  on  to  the  circumference  of  the 
lens.  Repeated  dissections,  and  the  substantial  testimony  of  Soem- 
mering, J have  satisfied  me  that  the  retina  cannot  be  fairly  traced 
beyond  the  greater  circumference  of  the  impressions  made  on  the 
vitreous  humour  by  the  ciliary  striae  of  the  Choroides.  When  the 
eye  is  slightly  macerated,  the  retina  ahvays  parts  from  the  vitreous 
humour  at  this  line;  moreover,  vdien  its  structure  is  still  more  slightly 
changed  by  freezing  and  then  thawdng,  the  retina  manifests  a decided 
preference  to  separate  there,  and,  under  the  most  careful  dissection, 
it  is  very  difficult  to  prevent  it.  In  addition  to  these  considerations, 
there  is  a well  marked  change  of  colour  at  the  line  mentioned : in 
front  of  this  line,  the  surface  is  transparent  when  cleaned  from  the 
pigmentum  nigrum ; whereas,  if  it  were  retina,  it  should  be  the 
colour  of  ground  glass,  as  is  usual  in  the  dead  body : also  the  veins 

t Anat.  Atlas,  Fig.  570. 


* Huschke,  p.  650. 


t leones  Oculi  Humani. 


THE  BALL  OF  THE  EYE. 


457 


of  the  retina  never  trespass  beyond  this  line,  but  are  seen  to  cruise 
along  it. 

Most  anatomists  teach  that  the  retina  is  an  expansion  of  the  optic 
nerve.  Bichat  believed  that  the  latter  terminated  at  the  bulb,  and 
that  the  retina  was  another  part  of  the  structure,  but  still  consisting 
of  the  same  sort  of  nervous  matter.  The  latter  opinion  is  probably 
the  more  strictly  correct,  because  there  is  more  pulpy  matter  in  a 
section  of  the  retina  than  can  be  found  in  the  same  length  of  the 
optic  nerve. ' Also,  if  the  retina  were  simply  an  expansion  of  the  nerve 
without  any  addition  of  matter  to  it,  it  should,  from  its  hollow  glo- 
bular shape,  be  thinner  in  the  middle,  where  it  is  most  expanded; 
than  it  is  where  the  expansion  first  begins  at  the  bulb  of  the  optie 
nerve,  but  this  is  not  the  case. 

The  retina  does  not  adhere  to  the  choroid  coat,  neither  to  the 
vitreous  humour  which  it  encloses,  except  at  the  line  mentioned ; 
when  this  line  of  attachment  is  broken,  the  retina  quickly  collapses. 

The  texture  of  the  retina  is  extremely  soft  and  pulpy ; in  the 
living  state,  it  is  probably  nearly  transparent,  but  this  can  only  be 
conjectured  from  the  readiness  with  which  the  vessels  of  the  choroid 
coat  can  be  seen  in  animals  destitute  of  pigmentum  nigrum.  It  is 
composed  of  two  principal  laminae,  of  which  the  external  is  nervous; 
and  the  internal,  or  that  next  to  the  vitreous  humour,  is  formed  of 
a fine  reticulated  cellular  membrane  with  blood  vessels  running 
through  it.  The  external  lamina  may  be  removed  by  a camel’s 
hair-pencil,  or  by  slight  putrefaction  and  washing,  so  as  to  leave  the 
internal  entire.  The  celebrated  John  Hunter  succeeded,  however, 
in  separating  the  two  laminae  fairly  from  each  other,  and  preserving 
them,  so  as  to  show  their  difference. 

Exactly  in  the  axis  of  the  eye,  or  at  its  centre,  posteriorly,  con- 
sequently, about  a line  and  a half  from  the  outer  side  of  the  bulb  of 
the  optic  nerve,  Soemmering*  discovered  a yellow  spot  (Macula  flava) 
of  a line  in  diameter,  with  a small  hole  in  its  middle,  made  by  a 
deficiency  of  nervous  matter.  From  the  optic  nerve  there  goes, 
towards  the  foramen,  a small  fold  of  the  retina,  two  and  a-half  lines 
long,  pointed  at  its  internal  end,  and  obtuse  or  bifurcated  externally. 
Unless  the  eye  be  fresh,  these  features  cannot  be  seen  distinctly,  for 
the  evaporation  of  the  aqueous  humour  causes  a collapse  or  wrinkling 
of  the  retina,  which  obscures  them.  But,  in  a perfectly  fresh  eye, 


* Comment.  Soc.  Reg.  Sc.  Gottingen,  1779i 


458 


NERVOUS  SYSTEM. 


which  is  well  managed,  they  may  be  seen  both  from  before  and  be* 
hind.  It  was  thought,  for  some  time,  that  the  yellow  spot  and  the 
foramen  were  peculiar  attributes  of  the  human  being : more  extended 
and  successful  observation  has  corrected  this  mistake,  by  detecting 
them  in  several  classes  of  animals. 

In  a careful  examination  of  the  eye  of  the  negro  Williams,*  I 
found,  in  three  hours  after  the  drop  fell,  (the  eye  consequently  being 
perfectly  fresh,)  the  retina  in  both  eyes,  of  the  colour  of  oiled  white 
paper  or  ground  glass : it  was  seen  distinctly  to  terminate  at  the 
beginning  of  the  ciliary  plaits  of  the  choroid.  The  spot  of  Soemmer- 
ing was  seen,  but  it  was  of  a sea  green,  oval,  a line  in  length,  the 
centre  marked  by  an  olive  spot : no  foramen  was  seen  satisfactorily. 
The  fold  of  the  retina,  running  to  the  entrance  of  the  optic  nerve, 
was  very  distinct,  as  well  as  the  button-like  appearance  of  the  nerve 
at  this  point. 

The  point  where  the  central  artery  of  the  Retina  enters,  is  called 
the  Macula  Lutea.  Michaelis  asserts,  that  around  it  the  filaments  of 
the  retina  are  arranged  in  arches,  of  which  one  part  meets  in  the 
macula  lutea,  the  next  in  succession  converge  regularly  towards  a 
line  stretching  from  the  macula  lutea.  f 

The  nervous  lamina  of  the  retina,  from  the  bulb  of  the  latter,  be- 
comes flattened  and  resolves  itself  into  primitive  filaments  of  uniform 
size,  without  knots  or  swellings ; they  anastomose  reciprocally  so  as 
to  form  a plexus  like  intertexture.  These  filaments  unite  with  one 
another  at  very  acute  angles,  and  have  scarcely  an  appreciable  inter- 
stice between  themselves,  hence  it  is  that  the  retina  has  the  appear- 
ance of  an  uninterrupted  membrane.  These  filaments  are  rated  at 
the  diameter  of  from  1-1000  to  the  1-415  of  a line,  and  are  said  to 
end  in  terminal  loops  like  other  nerves.  Upon  the  inner  face  of  the 
above  layer,  there  is  another  formed  of  globules,  and  called  by 
Krause  the  stratum  globosum,  it  is  composed  of  rounded  hyaline 
vesicles  with  an  excentric  nucleus  and  nucleoli.  By  some  it  is  ad- 
mitted to  exist  on  the  exterior  face  of  the  filamentous  nervous  coat 
and  also  in  its  thickness.  Within  this,  again,  is  a granular  layer, 
formed  of  yellow  globules,  and  resembling  the  corpuscles  of  the 
blood,  according  to  Valentin,  they  have  a diameter  of  about  the 
1-2 38  of  a line.  The  nervous  filaments  of  the  retina,  are  consi- 


* Executed  in  the  Moyamensing  Prison,  Aug.  9,  1839. 
t Muller,  reports  on  Nervous  System. 


THE  BALL  OF  THE  EYE. 


459 


dered,  by  Treviranus,  to  depart,  at  certain  points  from  their  regular 
course,  and  to  end  in  a papillary-like  structure  upon  the  internal  face 
of  the  membrane.  In  all  classes  of  vertebrated  animals,  this  struc- 
ture if  examined  recently  after  death,  has  the  appearance  of  a layer 
of  cylinders,  closely  packed  and  placed  with  one  extremity  towards 
the  centre  of  the  eye : if  undue  time  has  elapsed  since  death,  then 
the  appearance  is  simply  granular  as  described  by  Valentin. 

The  vascular  layer  of  the  Retina  ( Lamina  Vasculosa)  is  formed  by 
branches  of  the  central  artery  and  central  vein,  held  in  their  places 
by  cellular  substance.  The  artery  penetrates  the  nerve  at  the  dis- 
tance of  half  an  inch  or  an  inch  behind  the  eyeball,  and  passing 
along  the  centre  of  the  nerve,  reaches  the  interior  of  the  eye  in  the 
middle  of  the  bulb  of  the  optic  nerve.  From  that  point  it  divides 
into  four  or  five  branches,  which  pass  forwards  dividing  into  col- 
lateral branches,  and  finally  form  a very  delicate  arterial  intertexture, 
whose  filaments  are  distributed  to  the  oilier  coats  of  the  retina,  ex- 
cepting the  Tunica  Jacobi.  The  veins  undergo  a similar  arrange- 
ment, and,  finally,  collect  into  a central  vein  returning  by  the  same 
route  with  the  artery. 

It  is  stated  by  Langenbach  and  some 
others,  that  the  vessels,  of  the  retina  are 
attended  by  filaments  from  the  carotid 
ganglion,  and  from  the  ciliary  nerves. 

The  vessels  of  the  retina  have  no  com- 
munication, generally,  with  those  of 
the  choroid  coat,  some  anatomists* 
are,  however,  of  opinion,  that  such 
anastomosis  occurs,  at  the  bulb  of  the 
optic,  and  at  the  anterior  limit  of  the 
retina. 

The  yellow  spot  of  Scemmering,  and 
the  fold  of  the  retina,  are  surrounded 
by  a corona  of  the  blood  vessels,  and  the  opinion  is  entertained  by 
Huschke  and  others,  that  the  foramen  of  Soemmering,  is  not  ah  ac- 
tual perforation  but  a reduced  thickness  of  the  Retina,  which  corres- 
ponds with  my  own  experience. 


Fig.  43. 


Capillaries  in  vascular  layer  of 
Retina,  magnified  largely.  After 
Berres. 


* Henle— Teideman — Langenbach,  &c. 


460 


NERVOUS  SYSTEM. 


Fig.  44. 


“Structure  of  the  retina,  after  Treviranus. — A.  Portion  of  retina  of  a sheep  seen 
item  the  outer  side,  showing  the  cylindrical  fibres,  and  at  the  right  hand  border  some 
of  the  papillae,  in  which  the  fibres  terminate  on  the  inner  surface  of  the  retina ; B. 
papillae  seen  on  the  inner  surface  of  the  same  retina;  C.  a thin  perpendicular  section 
of  the  retina  of  the  hooded  crow  (Corvus  eornix),  which  had  been  hardened  by  mace- 
ration in  spirits;  a.  internal  lamina  of  choroid;  b,  layer  of  cellular  tissue,  in  which 
the  fibres  of  the  retina  radiate  out;  c.  perpendicular  portion  of  the  fibres  of  the  retina; 
d.  second  layer  of  cellular  tissue,  containing  a network  formed  by  branches  of  the 
arteria  centralis  retinae,  and  giving  a sheath  of  this  vascular  layer  of  retina  to  the 
nervous  fibres : e.  larger  nervous  fibres  which  have  acquired  this  sheath  ; /.  third 
cellular  layer  perforated  by  the  papillce  g.* 


Humours  of  the  Eye-Ball. 

The  Vitreous  Humourf  ( Humor  Vitreus,  Corpus  Vitreum,)  oc- 
cupies, with  the  exception  of  a very  small  part  just  behind  the  iris, 
the  whole  of  the  space  posterior  to  the  latter.  It  is,  therefore,  very 
nearly  globular ; is  in  contact  the  greater  part  of  its  extent  with  the 
retina,  and  at  least  as  far  as  the  latter  membrane  proceeds ; in  front 
it  is  in  contact  with  the  crystalline  humour,  and  from  the  margin  of 
the  retina  to  the  circumference  of  the  lens  it  is  in  contact  with  the 
ciliary  body,  meaning  thereby  the  ciliary  striae  and  processes  of  the 
choroides. 

Two  parts  compose  the  vitreous  humour, — the  hyaloid  membrane 
•and  a thin  fluid.  In  a natural  state  they  are  perfectly  transparent, 
and,  therefore,  cannot  be  readily  distinguished  from  each  other;  but 
by  immersion  in  spirits  of  wine  the  membranous  portion  is  brought  to 
the  colour  of  ground  glass,  and  may  then  be  studied  very  advanta- 
geously. The  membrane,  though  extremely  delicate,  is  generally 
strong  enough  to  permit  the  whole  vitreous  body  to  be  suspended  in 

* Muller’s  Physiol.,  p.  1122. 
t Anat.  Atlas,  Fig,  577. 


HUMOURS  OF  THE  EYE  BALL. 


461 


the  air  by  a thread  passed  through  it,  and  it  may  also  be  momentarily 
held  up  with  a pair  of  forceps.* 

The  Tunica  Hyaloidea  maybe  traced  as  a complete'capsule,  form- 
ing the  periphery  of  the  vitreous  humour ; and  from  the  internal  face 
of  this  capsule  there  proceeds  a great  number  of  partitions  dividing 
the  whole  cavity  into  cells  of  various  magnitude  and  form.  Some 
anatomists,  who  have  frozen  the  eye,  and  then  picked  out  the  pieces 
of  ice  from  the  cells,  have  the  notion  of  their  being  all  cuneiform, 
and  of  their  edges  pointing  forwards.  Our  preparations  in  the  ana- 
tomical cabinet  are  perfectly  satisfactory  in  exhibiting  the  existence 
of  an  arrangement  of  cells,  but  do  not  manifest  a regular  cuneiform 
shape  in  them. 

When  the  capsule  of  the  tunica  hyaloidea  has  got  to  the  distance 
of  two  lines,  or  thereabouts,  from  the  circumference  of  the  lens,  it 
divides  into  laminae,  which  reunite  at  the  circumference  of  the  lens. 
They  then  divide  again,  and  one  goes  before  the  capsule  of  the  lens, 
and  the  other  behind  it.  The  space  between  the  two  layers,  around 
the  circumference  of  the  lens,  is  the  Canal  of  Petit,  and  is  in  that 
part  of  the  tunica  hyaloidea  which  is  impressed  by  the  ciliary  striae 
and  ridges  of  the  choroides.  At  intervals,  passing  in  a radiated 
manner  from  the  exterior  to  the  interior  circumference  of  the  canal, 
there  is  a sort  of  shortening  or  constriction  of  it,  producing  partial 
septa  in  its  cavity ; so  that  when  the  canal  is  inflated,  it  seems  to 
consist  of  a series  of  small  cells,  arranged  circularly.  The  cells  of 
the  colon  will  give  some  idea  of  this  arrangement,  though  they  are 
produced  in  an  entirely  different  manner. 

The  fluid  part  of  the  vitreous  humour,  by  analysis,  gives  out  98. 
40  water,  .16  albumen,  and  the  remainder  is  saline.  In  consequence 
of  the  very  small  quantity  of  albumen  in  it,  neither  acids  nor  heat 
coagulate  it  to  a striking  degree. 

The  vitreous  humour  is  supplied  with  a branch  from  the  central 
artery  of  the  retina.  This  branch  does  not  convey  red  blood  but 
only  serum,  except  in  the  foetal  eye.  It  may  be  injected,  at  almost 
any  age,  with  size,  coloured  with  vermilion;  but  is  then,  of  course, 

* In  Williams  the  criminal,  executed  here,  as  stated  before,  I found  on  the  front 
of  one  hyaloid,  at  the  side  of  the  lens  an  opacity  of  three  by  six  lines,  resembling  an 
opacity  of  the  cornea,  it  was  just  where  the  tunica  hyaloidea  is  in  contact  with  the 
ciliary  plaits  of  the  choroid  and  was  at  first  mistaken  for  a metal-like  surface  of 
the  latter,  as  the  tapetum  of  the  lower  animals. 

You.  II.— 40 


462 


NERVOUS  SYSTEM. 


put  very  much  on  the  stretch.  It  has  been  well  described  by  Zinn. 
It  penetrates  the  vitreous  humour  near  the  optic  nerve,  and  is  dis- 
seminated by  very  fine  branches  on  the  periphery,  and  on  the  internal 
cellular  structure  of  the  tunica  hyaloidea.  M.  J.  Cloquet  has  de- 
scribed particularly  one  branch,  which,  running  through  the  centre  of 
the  vitreous  humour,  in  an  appropriate  canal,  is  spent  by  small  rami- 
fications upon  the  posterior  part  of  the  capsule  of  the  lens. 

Some  anatomists*  speak  of  a fluid  between  the  tunica  hyaloidea 
and  the  retina : when  it  does  exist,  it  in  all  probability  is  the  fluid  of 
the  vitreous  humour,  which  has  strained  through  the  tunica  hyaloidea 
after  death. 

The  Lensf  ( Lens  Crystallina ,)  or  the  Crystalline  Humour,  as  it 
is  very  generally  called,  is  placed  immediately  behind  the  pupil,  in 
a depression  on  the  front  of  the  vitreous  humour.  Its  shape  is  that 
of  a double  convex  lens,  of  which  the  posterior  convexity  is  greatest, 
being  the  section  of  a sphere  whose  diameter  is  from  four  to  five 
lines,  while  the  anterior  convexity  is  in  the  proportion  of  a sphere  of 
from  six  to  nine  lines.  The  usual  breadth  of  the  lens  is  about  three 
and  a-half  lines.  It,  however,  varies  its  shape  in  a remarkable  degree 
at  the  different  periods  of  life  ; immediately  after  birth  it  is  spheroidal, 
in  about  six  years  afterwards  its  lenticular  shape  is  well  marked,  and, 
subsequently,  it  becomes  more  flat  and  thin. 

The  lens  naturally  is  perfectly  transparent.  In  the  greater  part 
of  its  thickness  it  has  the  consistence  of  half  dissolved  glue,  but  its 
centre  is  much  more  solid ; this  change,  howrever,  is  effected  suc- 
cessively from  the  circumference  to  the  centre.  When  it  is  sub- 
jected to  the  mineral  acids,  to  heat,  to  alcohol,  and  several  other 
agents,  it  becomes  much  more  solid  throughout;  it  may  .then  be  sepa- 
rated, like  an  onion,  into  a series  of  concentric  lamellse,  subdivisible 
into  longitudinal  fibres.  Besides  these,  there  are  fibres  more  or  less 
oblique  which  hold  the  lamellse  together.  These  arrangements  pre- 
vail from  the  centre  to  the  circumference  of  the  lens ; and  between 
the  laminae  there  is  a diaphanous  humour  resembling  that  beween  it 
and  its  capsule4 

The  lens  has  a natural  but  adhering  division  into  three  equal  parts 
perfectly  alike  in  shape,  like  an  apple  which  one  may  have  divided 
in  that  way.  The  filaments  of  which  the  laminae  are  composed,  run 

* Bichat,  Anat.  Descrip. 

+ Anat.  Atlas,  Figs.  578,  579,  580. 

f J.  F.  Meckel. 


HUMOURS  OF  THE  EYE  BALL. 


463 


from  before  backwards,  and  have  their  ends  directed  towards  the 
limits  or  lines  marking  out  the  primary  division  into  three  parts. 
Sir  David  Brewster  has  shown  by  the  action  of  polarized  light,  that 
those  filaments  are  undulated  or  dentated  at  their  edges,  by  which 
means  they  adhere.  This  is  most  distinct  in  fishes.  The  fibres  of 
the  lens  are  considered  by  Schwann  to  be  originally  formed  from  a 
series  of  cells,  which  are  elongated  and  joined  together. 


Fig  45. 


A.  Represents  the  triple  division  of  the  lens  and  the  course  of  it s fibres.  B.  The 
tooth-like  or  serrated  margins  of  the  fibres  of  the  Lens.  After  Brewster.* 

Albumen  enters  very  largely  into  the  composition  of  the  lens, 
which  is  readily  proved  by  the  thorough  opacity  following  its  immer- 
sion in  spirits  of  wine.  It  is  considered  to  approach  the  structure  of 
cartilage  more  than  any  other  tissue,  also  in  its  mode  of  nutrition. 

The  lens  is  invested  by  a capsule  which  is  a complete  sac,  having 
exactly  its  shape,  but  separated  from  it,  to  a very  inconsiderable 
extent,  by  the  transparent  humour  just  alluded  to,  called  the  Liquor 
Morgagni.  The  capsule  is  covered  in  front  by  a layer  of  the  tunica 
hyaloidea  adhering  very  closely  to  it,  but  which,  in»  one  instance,  I 
was  enabled  to  peel  off  partially  in  the  eye  of  a sheep,  from  one  side 
to  the  other.  The  capsule  is  covered  in  like  manner,  on  its  pos- 
terior face  by  the  tunica  hyaloidea;  but  the  two  may  be  separated 
there  more  easily,  according  to  the  observations  of  Bichat.  Some 
of  the  most  distinguished  continental  anatomists  are  decidedly  in 
favour  of  the  capsule  of  the  crystalline  being  a complete  bag ; but  it 
is  rather  unsettled  whether  the  exterior  margin  of  the  capsule  bounds 
the  lesser  circumference  of  the  Canal  of  Petit,  or  whether  the  twTo 
layers  of  the  tunica  hyaloidea  unite  previously  at  the  circumference 


* Phil.  Trans.,  1833,  and  1836. 


464 


NERVOUS  SYSTEM. 


of  the  capsule.  The  latter  seems  to  be  the  opinion  of  M.  J.  Cloquet. 
The  late  Dr.  Physick,  in  some  cases  of  membranous  cataract,  suc- 
ceeded in  drawing  out  the  capsule  entire,  so  as  to  exhibit  its  whole 
extent  when  floated  in  water. 

The  capsule  in  front  of  the  lens  is  much  thicker  than  the  tunica 
hyaloidea,  and  its  difference  of  character  from  the  latter  appears  to 
me  to  be  very  strongly  marked ; for,  notwithstanding  its  immersion 
in  spirits  of  wane,  it  retains  its  transparency.  It  is  hard  and  elastic, 
and  when  clipped  with  fine  scissors,  gives  nearly  the  same  sensation 
as  the  thin  paring  of  a finger  nail  would  ; or,  as  has  been  observed 
by  Haller,  it,  in  this  respect,  resembles . the  cornea.  The  analogy 
with  the  cornea  eeases,  however,  at  this  point ; for  the  cornea  has 
always  so  much  albuminous  matter  in  it,  as  to  be  rendered  turbid 
when  it  is  immersed  in  alcohol.  The  posterior  half  of  the  capsule  of 
the  lens,  is  not  so  well  marked  either  by  its  thickness  or  specific 
characters  as  the  anterior,  yet  our  preparations  in  the  University  de- 
monstrate its  existence  equally  as  conclusively.  It  is  more  assimilated 
to  the  nature  of  the  tunica  hyaloidea. 

In  the  injected  fcetal  eye,  the  artery  of  the  tunica  hyaloidea  which 
comes  from  the  central  one  of  the  retina,  is  seen  to  furnish  several 
minute  ramifications  to  the  posterior  face  of  the  lenticular  capsule  ; 
some  of  its  branches  also  go  to  the  front  of  the  capsule,  but  the 
latter  part  is  furnished  principally  by  arterioles  from  the  ciliary  body 
of  the  choroides.  The  two  sets  of  arteries  anastomose  with  each 
other ; some  of  the  latter  are  also  spent  upon  the  membrana  pupil- 
laris. 

The  point  is  yet  doubtful  whether  any  of  these  arteries  penetrate 
into  the  body  itself  of  the  crystalline  humour.  Ruysch,  Albinus, 
and  Haller,  assert  the  fact  of  their  having  seen  and  injected  them  in 
the  human  species  and  in  animals,  and  J.  F.  Meckel  admits  their 
testimony.  Yet  there  are  not  many  anatomists  who  can  corroborate 
it  by  their  personal  observations.  It  is  sufficiently  reasonable  to  ad- 
mit it ; for  without,  we  cannot  conveniently  account  for  the  growth 
and  nutrition  of  the  lens,  as  well  as  the  morbid  changes  which  occur 
in  it.  It  should  be  observed  that  if  this  vascular  connexion  do  exist, 
it  is  a very  weak  one : for  the  lens  seems  to  be  simply  surrounded 
by  its  capsule  without  adhering  to  it. 

Some  veins  which  discharge  into  the  veins  of  the  choroid  coat, 
have  been  observed  by  Walter*  on  the  posterior  part  of  the  cap- 
* De  Oculis.  Berlin,  1778. 


HUMOURS  OF  THE  EYE  BALL. 


465 


sule.  It  should  be  continually  borne  in  mind  that  neither  the  arte- 
ries nor  veins  of  the  healthy  crystalline,  nor  of  its  capsule,  convey 
red  blood  ; in  which  respect  they  correspond  with  the  hyaMdea : 
for,  if  this  were  the  case,  vision  would  be  very  much  disordered  by 
it.  It  may  be  that  the  moats  or  specks  seen  in  ophthalmia  arise 
from  the  grosser  particles  of  the  blood  getting  into  these  serous  ves- 
sels, by  the  dilatation  of  the  latter. 

The  Lens  and  its  Capsule  are  devoid  of  nerves,  at  least  none  have 
been  as  yet  traced  into  them. 

The  Aqueous  Humour  ( Humor  Aquosus ) occupies  the  space  which 
is  between  the  anterior  face  of  the  crystalline  capsule,  and  the  poste- 
rior face  of  the  cornea.  This  space  is  unequally  divided  by  the  iris 
into  two  chambers  of  which  the  anterior  is  in  front  of  the  latter  mem- 
brane, and  the  posterior  behind  it.  In  consequence  of  the  convexity 
of  the  lens,  the  posterior  chamber  has  but  very  little  depth  just  be- 
hind the  pupil ; but  its  space  is  augmented  at  the  circumference  of 
the  crystalline,  so  as  to  leave'  room  for  the  floating  of  the  ciliary 
processes  and  for  the  motions  of  the  iris.  The  posterior  chamber 
is,  therefore,  a circular  vacuity  ; the  centre  of  which,  from  the  pro- 
jection of  the  centre  of  the  crystalline,  has  scarcely  any  appreciable 
depth.  The  anterior  chamber,  in  its  shape,  resembles  the  segment 
of  a sphere:  its  depth  depends  essentially  on  the  size  and  the  pro- 
jection of  the  cornea. 

The  aqueous  humour  is  perfectly  transparent,  and  almost  as  fluid 
as  water.  The  analysis  of  Berzelius  exhibits  98  parts  of  water,  too  of 
hydrochlorate  and  lactate  of  lime,,  tV  of  some  animal  matter  soluble 
in  water,  and  a very  small  quantity  of  albumen.  From  the  latter 
circumstance  it  will  be  understood  how  this  fluid  refuses  to  coagulate 
on  the  addition  of  alcohol  or  of  mineral  acids  to  it,  and  is  only  ren- 
dered in  a very  slight  degree  turbid  by  them.  The  rapidity  of  the 
exhalation  of  this  fluid  is  remarkable  ; when  the  whole  of  it  is  lost  in 
the  operation  for  cataract,  it  is  regenerated  in  from  twenty-four  to 
thirty-six  hours.  Its  source  has  been  sought  for  in  suppositive 
canals  and  glands,  but  the  more  probable  opinion  is,  that  it  may 
come  from  any  or  all  of  the  exhalant  arteries  of  the  chambers  of  the 
eye. 

Like  the  other  two  humours  of  the  Eye,  the  aqueous  is  furnished 
with  a capsule,  but  whether  it  is  complete  or  not  is  yet  undetermined.. 
By  immersing  the  eye  in  hot  water,  or  in  alcohol,  this  capsule  may 

*40 


466 


NERVOUS  SYSTEM. 


be  readily  detected  on  the  posterior  face  of  the  cornea,  and  to  the 
greater  circumference  of  the  iris;  it  may  even  be  traced  for  some  dis- 
tance on  the  front  surface  of  the  latter.  Some  of  the  French  anato- 
mists, as  Demours,*  Descemet,  and  J.  Cloquet,  have  asserted  that 
it  continued  also  through  the  pupil  to  line  the  posterior  chamber. 
An  opinion  like  this,  from  the  extreme  tenuity  of  the  part,  must  be 
rather  the  result  of  conjecture  than  of  accurate  observation : it  has, 
therefore,  never  found  its  way  with  full  force  into  the  writings  of 
anatomists.  The  loose  condition  of  the  pigmentum  nigrum  on  the 
posterior  face  of  the  iris,  and  on  the  ciliary  processes,  would  seem 
to  be  an  objection  to  the  existence  of  this  capsule  in  the  posterior 
chamber  of  the  eye.  But,  if  it  really  does  exist  there,  as  is  pretended 
by  M.  Portal,  who  supposes  it  to  be  derived  from  the  tunica  hya- 
loidea,  its  structure  is  incomparably  more  delicate  than  on  the  cor- 
nea, and  indeed  is  merely  gelatinous. 

The  Chambers  of  the  Eye,  till  the  seventh  month  of  foetal  exist- 
ence, and  sometimes  later,  are  perfectly  separated  from  each  other 
by  the  Membrana  Pupillaris,  called  so  from  its  position  in  the  pupil 
of  the  iris.  It  was  discovered  in  1740  by  Wachendorf,  and  is  some- 
times called  after  his  name.  It  is  a thin,  delicate,  and  transparent 
membrane,  which  is  stretched  aeross  the  pupil  from  its  circular  mar- 
gin, and  may,  by  its  colour,  be  readily  distinguished  from  the  iris, 
when  it  has  been  made  somewhat  turbid  by  alcohol. 

The  Membrana  Pupillaris  consists,  according  to  M.  J.  Cloquet,! 
of  two  laminae  placed  back  to  back,  of  which  the  foremost  is  a con- 
tinuation of  the  membrane  which  lines  the  anterior  chamber  of  the 
eye,  and  the  hindmost  of  that  which  lines  the  posterior  chamber. 
According  to  this,  it  may  be  noted  that  each  chamber  has  its  distinct 
capsule.  This  membrane  is  very  vascular;  some  of  its  arteries  are 
those  which  subsequently  form  the  internal  arterial  circle  of  the  iris, 
and  they  radiate  from  the  circumference  to  the  centre  of  the  mem- 
brane; others  come  directly  from  the  long  ciliary  arteries  and  others 
again  from  the  arteries  of  the  crystalline  capsule.  These  several 
vessels  are  found  principally  on  its  posterior  face.  Its  veins  have 
not  been  observed. 


* Dcmours,.  Lettre,  1767. 

t Journal  Unlverselle  des  Sc.,  Med.  Paris,  1818.  Mem.  sur  la  Memb.  Pupill.  Paris, 
3*818.. 


THE  EAR. 


467 


This  membrane  first  shows  itself  about  the  third  month  of  foetal 
existence,  and  is  most  perfect  at  the  seventh ; from  the  latter  period 
it  begins  to  decline,  by  disappearing  from  the  centre  to  the  circum- 
ference. At  the  ninth  month  it  consists  only  in  a few  loose  floccu- 
lent  shreds  adhering  to  the  pupil.  M.  J.  Cloquet  has  ascertained 
that  its  vessels  do  not  participate  in  its  destruction,  but  that  the 
arches  which  they  form  are  retracted  to  the  margin  of  the  pupil,  and 
there  form  the  lesser  arterial  circle  of  the  iris.  From  the  observa- 
tions of  Drs.  Jacob  and  Tiedemann,  it  appears  that  traces  of  the 
membrana  pupillaris  exist  for  ten  or  fifteen  days  after  birth.  The 
latter,  in  one  case,  injected  its  vessels  in  a fcetus  at  full  term.* 

The  Papillae  of  the  retina  are  supposed  to  determine  the  facility  of 
vision,  and  their  diameter  is  estimated  at  about  the  suos  of  an  inch 
by  Weber.  Ehrenberg  after  numerous  experiments  came  to  the 
following  conclusions.  The  smallest  visible  square  of  white  upon  a 
black  ground,  or  the  reverse,  is  about  the  ibs  of  an  inch.  A shining 
metallic  particle  as  gold  dust,  can  be  seen  of  a diameter  of  the  ukr 
of  an  inch.  If  objects  be  arranged  in  a close  linear  series  making 
for  example  a thread,  and  black;  this  thread  may  be  seen  of  a dia- 
meter not  less  than  the  53V  <j  of  an  inch,  when  held  before  a good 
light.  It  is  a matter  of  common  observation  that  an  object  invisible 
before  being  pointed  out,  afterwards  becomes  sufficiently  visible  by 
an  act  of  attention  to  it.f 


CHAPTER  III.. 

Of  the  Ear. 

The  ear,  the  organ  of  hearing  is  placed  principally  within  the 
petrous  portion  of  the  temporal  bone,  and  consists  in  the  External 
Ear  or  Auricle,  the  Tympanum,  and  the  Labyrinth. 

* Amer.  Med.  Jour.  vol.  i.  p.  192. 

t For  many  excellent  observationa  on  the  Physiology  of  Vision  the  reader  is  referred 
to  Muller,  loc.  cit. 


468 


NERVOUS  SYSTEM. 


SECT.  I. — OF  THE  EXTERNAL  EAR.'*' 

The  position  of  this  portion  of  the  organ  is  familiar  to  every  one. 
It  is  useful  in  collecting  the  rays  of  sound,  and  in  conveying  them 
to  the  more  internal  parts.  It  is  formed  by  the  structure,  exterior  to 
the  petrous  bone,  called,  in  common  language,  the  Ear;  and  by  a 
bony  canal  which  leads  internally  to  the  tympanum.  The  basis  of 
the  first  portion  is  fibro-cartilaginous,  on  which  circumstance  it  de- 
pends for  the  permanency  of  its  shape. 

The  ear,  of  common  language,  is  divided  into  two  parts,  Pinnaf 
and  Lobus:  the  former  is  the  most  extensive,  as  it  comprehends  all 
the  fibro-cartilaginous  portion : the  latter  is  attached  to  the  inferior 
margin  of  the  former,  and,  having  no  cartilage  in  its  composition,  is 
soft  and  pendulous. 

In  the  centre  of  the  external  ear  is  a deep  depression  called  the 
Concha;  in  the  bottom  of  it  is  the  orifice  of  the  canal  leading  to  the 
tympanum,  and  called  Meatus  Auditorius  Externus.  The  circum- 
ference of  the  pinna  is  convoluted  into  a scroll  called  the  Helix,  and 
commences  just  above  the  meatus  by  a ridge.  This  ridge  divides 
the  concha  into  two  unequal  cavities,  of  which  the  lower  is  the 
larger.  The  scroll  becomes  gradually  less  prominent,  till  it  termi- 
nates at  the  posterior  inferior  part  of  the  pinna,  in  the  lobus. 

The  Antihelix  is  the  slightly  curved  and  vertical  eminence  in  the 
middle  of  the  pinna:  its  lower  part  forms  the  posterior  boundary  of 
the  concha,  and  its  upper  part  bifurcates  into  two  small  ridges,  be- 
tween which  there  is  a depression  called  the  Scapha.  Between  the 
antihelix  and  the  posterior  half  of  the  helix,  is  an  oblong  depression, 
called  the  Fossa  Innominata. 

The  Tragus  is  an  elevation  of  the  pinna  placed  in  front  of  the 
concha,  and  inclining  somewhat  over  it;  opposite  to  it,  at  the  inferior 
part  of  the  concha,  is  the  Antitragus. 

The  fibro-cartilaginous  plate,  upon  which  the  external  ear  depends 
for  its  shape,  is  of  a thickness  very  nearly  uniform  ; of  course,  the 
ridges  and  depressions  on  its  exterior  surface  have  corresponding 
depressions  and  ridges  on  the  side  next  to  the  head.  It  is  inter- 

* Anat.  Atlas,  Figs.  584  to  588. 

. t From  some  resemblance  to  a certain  shell-fish. 


THE  EXTERNAL  EAR. 


469 


rupted  at  several  places  by  fissures ; for  example,  there  is  one  of 
considerable  size  ( lncisura  Major ) filled  up  with  ligamentous  matter, 
which  separates  the  upper  margin  of  the  tragus  from  the  beginning 
of  the  helix : there  is  another  between  the  lower  extremity  of  the 
antihelix  and  the  antitragus.  In  the  tragus,  there  are  two,  and 
sometimes  three,  small  narrow  ones,  ( Incisures  Minores ) said,  by 
Santorini,  to  be  filled  with  muscular  fibres;  but  the  latter  assertion 
does  not  correspond  with  the  observations  of  subsequent  anatomists, 
as  the  matter  appears  fibrous. 

The  external  ear  is  united  to  the  side  of  the  head  by  three  liga- 
ments. The  anterior  arises  from  the  root  of  the  zygomatic  process 
above  the  articulation  of  the  lower  jaw,  and  is  inserted  into  the 
pointed  production  of  cartilage  on  the  fore  part  of  the  helix.  The 
posterior  arises  from  the  swell  of  the  temporal  bone,  which  runs  into 
the  front  margin  of  the  base  of  the  mastoid  process,  and  is  inserted 
into  the  convex  side  of  the  concha,  at  the  beginning  of  the  meatus  au- 
ditorius.  The  superior  arises  from  the  temporal  aponeurosis,  and  is 
inserted  into  the  upper  part  of  the  concha.  These  ligaments  lie 
immediately  below  the  muscles  destined  to  move  the  ear,  and  are 
more  of  a condensed  lamina  of  cellular  substance,  than  distinct  liga- 
ments. 

The  Meatus  Auditorius  Externus,*  is,  in  the  adult,  an  inch  in 
length,  reckoning  from  its  external  orifice  to  the  membrane  of  the 
tympanum,  which  closes  it  inwardly.  It  is  about  three  lines  in 
diameter,  is  rather  oval  than  cylindrical,  and  somewhat  smaller  in 
the  middle  than  at  either  of  its  extremities.  It  runs  inwards,  with 
a slight  inclination  forwards ; the  exterior  half  is  formed  by  the  car- 
tilage of  the  pinna,  and  the  internal  half  by  the  temporal  bone : it 
departs  from  the  horizontal  course,  in  being  curved  at  its  middle 
where  the  two  sections  join.  This  curvature  has  its  convexity  up- 
wards, so  that  when  we  wish  to  look  to  the  bottom  of  the  canal,  the 
external  ear  must  be  pulled  upwards  and  backwards. 

The  external  half  or  portion  of  the  meatus  auditorius  is  formed  by 
a triangular  piece  springing  from  the  base  of  the  tragus  and  from  the 
inferior  anterior  part  of  the  concha.  This  portion  is  nearly  a tube, 
but  is  interrupted  above  and  behind  by  the  intervention  of  a dense 
fibrous  tissue,  continuous  with,  and  indeed  the  same  with  that  which 


* Anat.  Atlas,  Fig.  589. 


470 


NERVOUS  SYSTEM. 


joins  the  helix  and  the  tragus.  The  internal  margin  of  the  carti- 
laginous meatus  forms  a point  below ; and  adheres  closely  by  liga- 
ment to  the  asperities  on  the  margin  of  the  bony  meatus.  If  there 
were  no  fissures  in  the  external  ear,  it  would,  therefore,  be  almost 
immoveable. 

The  skin  covering  the  external  ear  is  more  delicate  than  in  most 
other  parts  of  the  surface  of  the  body.  Its  sebaceous  glands  or  fol- 
licles are  very  abundant,  and  in  infants  secrete  freely  their  peculiar 
fluid.  When  a slight  inflammation  occurs,  this  discharge  is  fre- 
quently purulent  without  erosion.  A duplication  of  the  skin,  con- 
taining a delicate  granulated  adeps  with  some  fibrous  matter,  consti- 
tutes the  lobe  of  the  ear. 

The  skin,  after  lining  the  concha,  descends  into  the  meatus  audi- 
torius,  and  lines  it  also  as  well  as  the  external  face  of  the  membrane 
of  the  tympanum.  It  adheres  moderately  to  the  cartilaginous  part 
of  the  tube,  and  more  tenaciously  to  its  fibrous  portions : between 
it  and  the  latter  are  found  many  small  reddish  bodies,  generally  oval, 
the  Glandulse  Ceruminosse,*  from  which  proceeds  the  earwax.f  The 
skin  is  extremely  thin  in  the  bony  meatus,  adheres  closely  to  its  pe- 
riosteum, and  is  highly  sensible  : where  it  forms  the  exterior  layer  of 
the  membrane  of  the  tympanum,  it  may  be  detached  from  the  latter 
with  the  slightest  force,  and  seems  to  be  converted  almost  entirely 
into  cuticle.  A slight  maceration  or  incipient  putrefaction  frequently 
enables  one  to  draw  the  cuticle  out  entire  from  the  meatus,  so  that  it 
looks  in  shape  like  the  finger  of  a small  glove. 

The  dermoid  lining  of  the  meatus,  at  its  external  orifice,  is  studded 
with  fine  hairs,  which  serve  to  keep  out  small  bodies  that  may  be 
floating  in  the  air.  A considerable  number  of  small  pores  are  also 
seen  in  it,  which  are  the  orifices  of  the  ducts  of  the  ceruminous 
glands.  The  discharge  of  the  latter,  when  first  secreted,  is  thin  and 
white : by  evaporation,  it  becomes  thick  and  yellow,  and  by  accu- 
mulating obstructs  the  passage. 

There  are  several  small  muscles  situated  on  the  external  ear, 
which  are  for  the  most  part  so  feebly  developed  that  they  cannot 
always  be  found,  and  when  they  do  exist  they  seem  more  like  the 

* Duverney,  (Euvres  Anatomiques. 

t Anat.  Atlas,  Fig.  143.  They  are  placed,  according  to  Buchanan,  for  the  major 
part,  in  the  middle  and  superior  face  of  the  meatus,  and  their  number  he  estimates 
at  from  one  to  two  thousand.  Physiolog.  illustrations.  1825. 


EXTERNAL  EAR. 


471 


rudiments  of  what  is  well  marked  in  animals,  than  intended  for  a 
special  purpose  in  the  human  body. 

1.  The  Helicis  Major  is  an  oblong  fasciculus,  situated  on  the  front 
of  the  helix.  By  its  lower  end  it  is  attached  to  the  point  of  cartilage 
on  the  front  of  the  helix,  and  its  other  extremity  extends  to  the  top 
of  the  latter. 

2.  The  Helicis  Minor  is  a small  square  fasciculus,  also  on  the 
front  of  the  helix,  between  the  folded  margin  of  the  latter  and  the 
inferior  half  of  the  helicis  major. 

3.  The  Tragicus  is  a square  transverse  fasciculus,  on  the  front  sur- 
face of  the  tragus,  near  its  margin  : its  upper  extremity  sometimes 
runs  into  the  helicis  major. 

4.  The  Antitragicus  is  a small  oblong  fasciculus,  which  arises 
from  the  upper  extremity  of  the  antitragus,  and  going  upwards  it  is 
inserted  into  the  inferior  extremity  of  the  antihelix. 

5.  The  Transversus  Auriculae  is  on  the  internal  surface  of  the 
pinna.  It  arises  from  the  prominence  of  the  concha,  and  is  inserted 
into  the  hollow7  dorsum  of  the  antihelix. 

6.  The  Dilatator  Conchae,  or  Musculus  Incisurae  Majoris,  of 
Santorini,  is  a small  narrow  band,  and  extends  from  the  front  of  the 
helix  across  the  great  fissure,  outwards  and  downwards  to  the  tragus. 
It  dilates  the  concha. 

There  are  some  other  muscles  which  may  be  uniformly  found, 
and  are  intended  to  move  the  external  ear  upon  the  side  of  the 
head,  though  from  the  want  of  exercise  there  are  very  few  in- 
dividuals capable  of  making  them  contract.  They  are  as  fol- 
lows : 

1.  The  Attollens  or  Superior  Auriculae  is  placed  on  the  side  of  the 
head  beneath  the  integuments  : it  is  a broad  thin,  and  somewdiat 
triangular  muscle,  which  arises  from  the  inferior  margin  of  the  ten- 
don of  the  occipito-frontalis,  and  from  the  temporal  aponeurosis..  It 
becomes  narrower  in  its  descent  and  is  inserted,  tendinous,  into  the 


472 


NERVOUS  SYSTEM. 


upper  end  of  the  pinna,  by  the  elevation  corresponding  with  the 
scapha. 

Its  name  implies  its  action,  to  be  that  of  raising  the  pinna. 

2.  The  Retrahens  or  Posterior  Auriculae,  consists  in  two  or  three 
oblong  fasciculi,  placed  parallel,  and  one  above  the  other.  It  arises 
from  the  mastoid  portion  of  the  temporal  bone,  above  the  mastoid 
process,  and  is  inserted  tendinous  into  the  convex  side  of  the  concha 
near  the  meatus  auditorius. 

It  draws  the  pinna  backwards. 

3.  The  Anterior  or  Attrahens  Auriculae  is  a small  quadrangular 
slip,  just  above  the  root  of  the  zygomatic  process.  It  arises  from 
the  temporal  fascia,  and  is  inserted  tendinous  into  the  fore  part  of 
the  helix  just  above  its  beginning. 

It  draws  the  pinna  forwards  and  upwards. 

SECT.  II. — OF  THE  TYMPANUM. 

The  Tympanum  is  the  middle  portion  of  the  organ  of  hearing, 
being  interposed  between  the  meatus  auditorius  and  the  labyrinth. 
Its  depth  is  about  three  lines,  its  antero-posterior  diameter  about 
six  and  its  vertical  diameter  rather  more,  though  from  the  general  in- 
equality of  the  cavity,  and  its  communication  with  adjoining  cavities, 
it  is  not  easy  to  fix  upon  very  precise  measurements. 

The  Membrana  Tympani , is  a complete  membranous  septum, 
interposed  between  the  meatus  externus  and  the  tympanum.  It  is 
placed  very  obliquely,  so  that  its  upper  edge  inclines  outwards,  and 
its  under  edge  inwards ; the  latter,  therefore,  forms  a very  acute  en- 
tering angle  with  the  inferior  part  or  floor  of  the  meatus,  and  gives 
to  that  portion  of  the  meatus  an  additional  length,  which  renders  it 
difficult  to  see  to  its  bottom.  The  membrane  of  the  tympanum  is 
nearly  circular,  and  has  its  circumference  adhering  very  closely  to 
the  external  orifice  of  the  tympanum.  It  is  slightly  tense,  and  has 
its  middle  drawn  inwards  by  being  attached  to  the  handle  of  the 
malleus. 

The  membrani  tympani  consists  of  four  laminse;  the  two  exte- 
rior of  which,  being  the  cuticle  and  the  cutis  vera,  which  line  the 
meatus  auditorius,  are  easily  detached,  as  mentioned  before,  and 


THE  TYMPANUM. 


473 


seem  scarcely  to  adhere  to  the  layer  below.  The  third  layer  is  the 
proper  membrane,  and  is  distinguished  by  its  dryness  and  by  its 
transparency.  Sir  Everard  Home  was  enabled  to  detect  radiated 
muscular  fibres,  forming  it  in  the  elephant.*  In  the  human  subject, 
its  fibrous  character  is  best  seen  on  its  internal  face,  but  the  radiated 
arrangement  is  not  so  distinct.  Caldani  considers  it  as  formed  by 
filaments,  decussating  each  other  at  right  angles,  and  intermixed 
with  blood  vessels.f  The  internal  layer  is  a continuation  of  the 
lining  membrane  of  the  tympanum ; it  is  separated  with  some  diffi- 
culty, owing  to  its  tenuity. 

The  proper  membrane  of  the  tympanum,  when  successfully  in- 
jected, exhibits  a high  degree  of  vascularity;!  though,  in  its  natural 
state,  but  very  few  red  blood  vessels  are  seen  in  it. 

The  floor  of  the  tympanum,  or  the  side  next  to  the  labyrinth,  pre- 
sents an  unequal  surface.  In  its  middle  is  aw7ell  marked  rising,  the 
Promontory,  ( Promontorium ,)  formed  by  one  end  of  the  labyrinth. 
Just  above  the  superior  margin  of  this  prominence,  near  its  centre, 
is  an  oval  opening,  called,  from  its  shape,  Foramen  Ovale,  or 
Fenestra  Ovalis;  having  its  long  diameter  horizontal,  its  superior 
margin  rounded  or  concave,  and  its  inferior  straight.  At  the  pos- 
terior inferior  part  of  the  promontory  is  another  opening,  which, 
though  somewhat  triangular,  is  called  the  Foramen  Rotundum,  or 
Fenestra  Rotunda,  and  in  the  dried  bone  leads  to  the  cochlea,  but 
is  naturally  stopped  by  the  lining  membrane  of  the  tympanum.  Ac- 
cording to  M.  Ribes,  this  membranous  plug  has  also  two  other  layers, 
an  internal  one,  the  continuation  of  what  lines  the  cochlea,  and  a 
middle  one,  which  is  peculiar.  In  these  respects,  there  is  a corres- 
pondence with  the  membrana  tympani. 

The  Eminentia  Pyramidalis  is  a small  conical  eminence  projecting 
from  the  posterior  part  of  the  tympanum,  on  a line  with  the  fenestra 
ovalis.  It  is  hollow,  contains  a muscle,  and  communicates  at  the 
other  end  with  the  Canal  of  Fallopius.  Lower  down,  and  more  ex- 
ternally, there  is  a small  orifice,  ( Apertura  Chorda,)  through  which 
the  nerve  called  Chorda  Tympani  passes. 

* Philosophical  Transactions,  for  1800.  London. 

t Plate  XCVIII.  Anat. 

J Ruyschii,  Epist.  Anat.  Probl.  viii.  Also  Anatomical  Museum,  Univ.  Penns.  ’ 

Vol.  II.— 41 


474 


NERVOUS  SYSTEM. 


The  Mastoid  Portion  of  the  Temporal  bone,  in  the  adult,  abounds 
in  large  cells  or  sinuses,  which  communicate  freely  with  one  ano- 
ther. They  are  distinct  from  the  diploic  structure  of  the  bone,  as 
they  contain  no  medulla,  and  are  lined  by  a continuation  of  the 
interna]  membrane  of  the  tympanum,  which  is  extremely  thin  upon 
them.  The  orifice  of  communication  between  these  cells  and  the 
tympanum,  is  placed  at  the  superior  posterior  part  of  the  latter : it 
is  rough  and  irregular,  and  partially  occupied  by  the  short  leg  of  the 
incus.  Just  in  front  of  this  opening,  the  cavity  of  the  tympanum 
is  extended  vertically,  for  the  purpose  of  accommodating  the  body 
of  the  malleus  and  of  the  incus,  whereby  they  are  in  a great  degree 
concealed,  unless  the  corresponding  margin  of  the  tympanum  be 
cut  awTay. 

At  the  fore  part  of  the  tympanum  is  the  Eustachian  Tube,*'  W'hich 
runs  for  six  or  eight  lines  in  the  substance  of  the  petrous  bone,  near 
its  exterior  margin  ; and  then  terminates  in  a cartilaginous  and  mem- 
branous portion,  which  communicates  with  the  pharynx  at  the  pos- 
terior naris.  The  latter  extremity  of  the  Eustachian  Tube  is  placed 
on  a line  with  the  posterior  end  of  the  inferior  spongy  bone.  Its 
orifice  is  rounded  or  oval,  is  large  enough  to  admit  the  tip  of  the 
little  finger,  and  reposes  against  the  side  of  the  internal  pterygoid 
process  of  the  sphenoid  bone.  Though  almost  within  the  precincts 
of  the  posterior  naris,  this  orifice  is  to  be  considered  as  opening  into 
the  pharynx. 

This  canal,  in  its  whole  length,  measures  nearly  two  inches,  and, 
with  the  exception  of  the  portion  in  the  petrous  bone,  is  cartilaginous 
and  membranous.  The  cartilage  is  a single,  thick  triangular  plate, 
flat,  and  adhering  by  one  of  its  edges  to  the  internal  pterygoid  pro* 
cess.  The  under  part  of  the  tube  is  membranous,  thin  and  affords 
attachment  to  some  of  the  muscles  of  the  soft  palate.  Its  course  is 
nearly  horizontal,  backward  and  outward. 

It  is  lined  in  its  whole  extent,  by  a very  fine  mucous  membrane 
continuous  with  that  of  the  pharynx  and  of  the  tympanum.  This 
membrane  is  thickened  at  its  anterior  extremity  by  the  mucous  glands 
beneath  it,  which  assist  in  giving  the  marked  elevation  to  its  ori- 
fice. The  canal  diminishes  as  it  goes  backward,  so  as  to  receive 
with  difficulty  a small  probe. 


Anat.  Atlas,  Fig.  G14, 


THE  TYMPANUM. 


475 


By  removing  carefully  the  mucous  membrane  of  the  pharynx  at 
and  below  the  origin  of  the  Eustachian  tube,  there  will  be  found  a 
fasciculus  of  muscular  fibres,  a line  or  two  wide,  sometimes  less. 
This  fasciculus  arises  from  the  upper  part  of  the  Palato  Pharyngeus, 
and  crossing  over  the  external  face  of  the  Levator  Palati,  goes  to  be 
inserted  into  the  orifice  of  the  Eustachian  tube.  One  division  of  it 
reaching  the  tip  of  the  cartilaginous  portion,  and  the  other  the  edge 
of  the  membranous  part. 

When  this  fasciculus  contracts,  it  dilates  the  orifice  of  the  Eusta- 
chian tube.* 

Parallel  with  the  bony  part  of  this  canal,  but  above  it,  and  sepa- 
rated by  a very  thin  partition  of  bone,  is  another  canal  which  lodges 
a muscle  of  the  malleus.  On  the  outer  side  of  the  Eustachian  tube 
is  the  glenoid  foramen,  by  which,  in  the  dried  bone,  the  tympanum 
communicates  with  the  glenoid  cavity  ; in  the  recent  state  the  fora- 
men receives  the  long  process  of  the  malleus  and  its  muscle,  and 
transmits  the  chorda  tympani. 

There  are  four  bones  in  the  tympanum,  which,  being  succes- 
sively articulated  with  each  other,  form  a chain,  one  end  of  which 
is  fastened  to  the  membrana  tympani,  and  the  other  end  rests  upon 
the  foramen  ovale.  They  are  the  Malleus  ; the  Incus  ; the  Orbicu- 
lare  ; and  the  Stapes,  f 

The  Malleus  forms  the  fore  part  of  the  chain,  and  is  placed  al- 
most vertically.  Its  superior  extremity  is  the  head,  which  is 
rounded,  with  the  exception  of  the  posterior  face,  where  a small 
concavo-convex  surface  is  observable,  for  its  articulation  with  the 
incus.  Its  lower  extremity  is  long  and  tapering,  inclines  inwardly, 
terminates  by  a little  knob,  and  forms  an  angle  with  the  part  above; 
this  portion  is  the  manubrium,  and  adheres  its  whole  length  to  the 
membrana  tympani,  commencing  at  the  superior  margin  of  the  latter, 
and  insinuating  itself  between  the  internal  and  the  proper  layer,  as 
far  as  the  centre  of  the  membrane.  It  is  this  adhesion  with  the  in- 
clination inwards  of  the  manubrium,  that  causes  the  membrane  to 
be  depressed  in  its  centre. 

Between  the  head  and  the  manubrium  is  a short  portion  called 
the  neck.  From  the  superior  external  extremity  of  the  manubrium 


* See  Palato-Pharyngeus. 


t Anat.  Atlas,  Figs.  598  to  597. 


476 


NERVOUS  SYSTEM. 


there  proceeds  outwardly  the  short  process,  ( Processus  Brevis;) 
and  from  the  front  of  the  neck,  there  proceeds  the  long  and  very 
delicate  process,  concave  externally  and  convex  internally,  which 
is  insinuated  into  the  glenoid  foramen,  and  is  the  Processus  Longus, 
or  Gracilis. 

The  Incus  is  behind  the  malleus,  and  is  also  upright.  It  consists 
in  a body  and  two  branches,  which  diverge  very  considerably,  and 
has  a general  resemblance  to  a molar  tooth  with  two  roots,  one  of 
which  has  been  broken.  The  body  presents,  on  its  fore  part,  a deep 
concavity,  which  articulates  with  the  convex  head  of  the  malleus. 
The  branch  which  arises  from  the  back  part  of  the  body  is  hori- 
zontal, looks  into  the  orifice  of  the  mastoid  cells,  and  is  much 
shorter  than  the  other.  The  inferior  branch  is  long,  upright,  taper- 
ing, and  nearly  parallel  with  the  manubrium  of  the  malleus,  but 
somewhat  within  it. 

The  Orbiculare  is  a very  small  flattened  sphere  of  bone,  which 
articulates  with  the  lower  end  of  the  long  process  of  the  incus,  and 
in  adult  life  is  most  generally  fused  into  it,  so  as  to  lose  its  distinc- 
tive character  : the  latter  change  sometimdS  occurs  even  in  early 
infancy.- 

The  Stapes  is  the  last  of  the  chain.  It  resembles  very  strongly 
the  common  stirrup  iron,  from  whence  its  name,  and  is  placed  hori- 
zontally at  right  angles  to  the  incus,  being  separated  from  the  extre- 
mity of  the  long  process  of  the  latter  by  the  os  orbiculare,  and  being 
directed  inwards  to  the  foramen  ovale.  It  is  composed  of  a head, 
two  crura,  and  a base. 

The  head  is  oblong  and  flattened  : it  has  a slight  depression 
where  it  joins  the  orbiculare.  The  crura  are  slightly  curved,  with 
the  concavities  towards  each  other : the  anterior  is  somewhat 
straighter  than  the  posterior,  and  is  also  shorter.  They  are  both 
excavated,  longitudinally,  on  their  concave  surfaces,  and  between 
them  is  stretched  a process  of  the  lining  membrane  of  the  tympa- 
num. The  base  is  precisely  adapted  to  the  fenestra  ovalis,  and  is 
connected  to  it  by  the  lining  membrane  of  the  tympanum,  but  not 
so  closely  as  to  prevent  it  from  executing  slight  vibratory  move- 
ments. 

Between  the  malleus  and  the  incus  there  is  a moveable  articula- 


THE  TYMPANUM. 


477 


'don  with  the  synovial  membrane,  but  the  other  joints  of  the  chain 
are  simply  ligamentous. 

This  chain  of  bones  is  moved  by  several  muscles,  which  influence 
the  degree  of  tension  of  the  membrana  tympani. 

1.  The  Laxator  Tympani  arises  from  the  posterior  end  of  the 
spinous  process  of  the  sphenoid  bone,  and  passing  behind  the  arti- 
culation of  the  lower  jaw  into  the  glenoid  foramen,  is  inserted,  ten- 
dinous, along  the  processus  gracilis  of  the  malleus. 

It  draws  the  malleus  forwards  and  outwards,  so  as  to  relax  the 
membrana  tympani. 

2.  The  Tensor  Tympani  is  placed  in  the  canal  just  above  the 
Eustachian  tube.  It  arises  from  the  posterior  extremity  of  the  carti- 
laginous portion  of  the  latter,  and  having  got  into  the  tympanum,  is 
changed  into  a small  tendon,  which  going  outwardly,  is  inserted 
into  the  neck  of  the  malleus,  just  below- its  processus  gracilis. 

It  draws  the  malleus  inwardly ; consequently  makes  tense  the 
membrana  tympani,  and  drives  the  stapes  into  the  fenestra  ovalis. 

3.  The  Stapedius  arises  from  the  bottom  of  the  cavity  in  the 
pyramid,  and  terminates  in  a small  round  tendon,  which,  going 
through  the  apex  of  the  latter,  is  inserted  into  the  head  of  the 
stapes. 

It  draws  the  stapes  backwards,  and  perhaps  fixes  it  more  firmly 
by  its  contractions. 

4.  There  is  a fourth  muscle-  mentioned  by  anatomists,  the  exist- 
ence of  which  is  more  equivocal ; it  is  called  the  Laxator  Tympani 
Minor.  It  is  said  to  arise  from  the  superior  margin  of  the  orifice  of 
the  tympanum,  and  to  be  inserted  into  the  processus  brevis  of  the 
malleus.  It  is  by  some  considered  only  as  a ligament,  to  which, 
opinion  I am  inclined. 

Of  the  Lining  Membrane  of  the  Tympanum.. 

This  membrane  is  in  continuation  of  the  lining  membrane  of  the 
pharynx,  being  introduced  into  the  tympanum  through  the  Eusta- 

41* 


478 


NERVOUS  SYSTEM. 


ehian  tube.  It  covers  completely  the  surface  of  the  tympanum,  and  is 
reflected  over  its  little  bones  so  as  to  give  them  a covering  also : in 
addition  to  which,  it  lines  such  of  the  mastoid  cells  as  communicate 
with  the  tympanum. 

This  membrane  is  extremely  delicate  : on  its  surface,  adjacent 
to  the  bones,  it  is  somewhat  fibrous,  and  thereby  resembles  perios- 
teum ; but  the  other  surface  has  the  characters  of  the  mucous  mem- 
branes generally,  in  the  nature  of  its  secretion,  and  in  its  vascularity, 
which  is  very  strongly  marked  in  inflammations,  and  by  fine  injec- 
tions. Bichat  mentions,  that  in  certain  catarrhal  affections  its  mu- 
cous secretion  is  so  abundant  as  to  fill  the  whole  cavity  of  the  tym- 
panum, and  that  without  ulceration.  Sometimes,  in  such  cases,  the 
membrane  of  the  tympanum  is  ruptured,  and  the  discharge  finds  its 
way  out  through  the  meatus  externus,  presenting  itself  in  a purulent 
state,  as  if  an  abscess  had  formed  in  the  ear. 

SECT.  III. — OF  THE  LABYRINTH.* 

The  Labyrinthf  ( Labyrinthus ) is  placed  on  the  inner  side  of  the 
tympanum,  in  the  thickness  of  the  petrous  bone.  Its  exterior  parietes 
are  bone,  but  internally  there  is  a membranous  structure,  having, 
in  many  respects,  the  same  shape.  It  is  got  at  with  great  difficulty 
in  the  adult,  owing  to  the  compactness  of  the  petrous  bone  which 
envelops  it ; but  in  the  foetus  of  the  full  period,  where  it  is  almost  as 
large  as  in  the  adult,  the  surrounding  bone  is  of  a softer  and  more 
spongy  texture,  and  may  be  pared  away  with  a pen-knife  without 
much  trouble.  In  the  latter  case,  the  parietes  of  the  bony  labyrinth 
remain  about  the  thickness  of  an  egg-shell,  and  have  very  much  the 
same  degree  of  consistency  and  strength. 

The  bony  labyrinth  consists  of  three  portions:  the  Vestibulum, 
the  Semicircular  Canals,  and  the  Cochlea. 

The  Vestibulum  is  the  cavity  to  which  the  foramen  ovale  leads ; 
it,  with  the  cochlea,  occasions  the  protuberance  into  the  tympanum, 
known  as  the  promontory.  It  is  an  irregular  rounded  excavation, 
the  surface  of  which  is  impressed  by  its  contents ; thus,  at  the  supe- 

* Antonio  Scarpa,  Disquisit.  de  Auditu  et  Olfacto. 
t Anat.  Atlas,.  Figs.  598  to  604,  inclusive. 


THE  LABYRINTH. 


479 


rior  posterior  and  external  part,  next  to  the  semicircular  canals, 
there  is  a superficial  Fossa,  called,  from  its  shape,  Semi-Elliptica; 
and  at  its  anterior  and  inferior  part,  nearer  the  cochlea,  another, 
called  Fossa  Hemi-Spherica.  These  fossae  are  marked  off  from  each 
other  by  a ridge  of  bone,  at  the  lower  end  of  which  there  is  a third 
fossa  between  the  other  two,  called  by  Soemmering,  Cavitas  Sulci- 
formis. 

There  are  seven  orifices  belonging  to  the  vestibulum  besides  the 
foramen  ovale ; five  at  its  posterior  part  leading  into  the  semicircular 
canals  ; one  anteriorly  leading  into  the  upper  scala  of  the  cochlea  : 
and  the  last  placed  in  its  internal  paries  is  the  aqueduct  of  the  ves- 
tibule. In  addition  to  these  orifices,  the  parietes  of  this  cavity  are 
cribriform  in  the  fossa  semi-elliptica  and  near  the  foramen  rotundum.* 

The  Semicircular  Canals  ( Canales  Semicircular es ) are  at  the  pos- 
terior extremity  of  the  vestibulum.  They  are  three  in  number,  and 
are  named  from  their  relative  situation,  Superior  or  Anterior,  Pos- 
terior or  Inferior,  and  External.  Each  one  forms  rather  more  than 
the  half  of  a semicircle,  and  has  its  cavity  about  half  a line  in  dia- 
meter : their  orifices  are  somewhat  dilated  beyond  this  measurement. 
The  apparent  thickness  of  their  parietes  is  greater  in  the  adult  than 
in  the  infant. 

The  Superior  Canal  runs  from  without  inwards  and  backwards. 
Its  anterior  orifice  is  above  the  fenestra  ovalis,  and  is  enlarged  into 
an  ampulla  or  elliptical  cavity.  At  its  posterior  extremity,  it  joins 
the  upper  extremity  of  the  inferior  canal,  so  that  a common  trunk  is 
thus  formed,  the  orifice  of  which  is  at  the  internal  posterior  part  of 
the  vestibulum,  and  is  dilated  into  the  shape  of  a funnel,  f 

The  Posterior  or  Inferior  Canal  is  nearly  vertical ; has  its  con- 
cavity in  front,  and  its  convexity  behind,  and  joins,  as  just  remarked, 
with  the  superior;  its  inferior  orifice,  which  is  near  the  foramen 
rotundum,  is  also  enlarged  into  an  ampulla  or  elliptical  cavity.  It 
is  the  longest  of  the  three  canals,  and  has  its  ends  nearer  together. 

The  External  Canal  is  nearly  horizontal,  and  is  placed  in  the 
space  left  by  the  divergence  of  the  other  two.  It  is  the  shortest  and 
the  largest  of  the  three.  Its  exterior  orifice  is  also  enlarged  into  an 
ampulla  or  elliptical  cavity,  and  is  just  behind  the  foramen  ovale,  or 


Ant.  Scarpa,  loc.  cit. 


t Scarpa,  loc.  cit. 


480 


NERVOUS  SYSTEM. 


below  the  ampulla  of  the  upper  canal ; the  internal  orifice  is  below 
the  common  opening  of  the  other  two  canals. 

It  is  the  union  of  the  superior  and  of  the  posterior  canals  at  one 
of  their  extremities,  which  reduces  the  number  of  openings  into  the 
vestibulum,  from  the  semicircular  canals,  to  five  instead  of  six. 

The  Cochlea*  forms  the  fore  part  of  the  labyrinth,  and  resembles 
very  strongly  the  shell  of  the  common  snail.  Its  base  is  the  bottom 
of  the  meatus  auditorius  internus,  and  its  apex  is  directed  towards 
the  cavity  of  the  tympanum,  so  that  the  axis  of  the  cochlea  is  turned 
downwards  and  outwards.  It  consists  in  a conoidal  tube  wound 
spirally  twice  and  a half,  around  a column  of  bone  termed  the  Mo- 
diolus. f The  tube  then  of  course  diminishes  in  size  from  the  base 
to  the  apex  of  the  cochlea. 

This  conical  tube  is  divided  in  its  length  by  a plate  called  Lamina 
Spiralis.  Of  the  two  compartments  thus  formed,  and  called  Scalse 
or  stairs,  one  is  above  the  other.  The  inferior  is  the  larger,  and 
communicates  at  its  base,  through  the  foramen  rotundum,  with  the 
tympanum;  it  is,  therefore,  called  Scala  Tympani.  The  other  com- 
partment communicates  at  its  base  with  the  vestibulum,  and  is,  there- 
fore, called  Scala  Vestibuli. 

The  Modiolus  is  of  a conical  shape,  and  cribriform : one  canal, 
larger  than  the  others,  runs  from  its  base  to  its  summit.  This  canal 
is  surrounded  by  many  others,  which  diminish  successively  as  they 
advance  towards  the  apex,  and  terminate  in  orifices  upon  the  lamina 
spiralis.  This  cribriform  arrangement  of  the  modiolus  is  the  Tractus 
Spiralis  Foraminulosus.  The  base  of  the  modiolus  is  towards  the 
meatus  auditorius  internus;  and  its  point  does  not  go  to  the  apex  of 
the  cochlea,  but  stops  short  of  it,  and  is  expanded  into  a cavity  called 
the  Infundibulum,  the  base  of  wdiich  is  towards  the  apex  of  the  cochlea. 
That  portion  of  the  apex  of  the  cochlea  which  covers  over  the  infun- 
dibulum, is  the  Cupola. 

It  w7as  just  mentioned  that  the  lamina  spiralis  divides  the  cochlea 
into  twro  tubes  ; the  septum  thus  formed,  does  not,  however,  run 
their  whole  length,  for  it  ceases  in  the  infundibulum  by  a spall 
crooked  process  of  bone,  called  the  Hamulus  Cochleae.  The  lamina, 

* Anat.  Atlas,  Figs.  608  to  610,  inclusive. 

| From  its  being  like  the  nave  or  stock  of  a wheel  in  which  the  spokes  are  fas- 
tened. 


THE  MEMBRANOUS  LABYRINTH.  481 

when  examined  by  strong  glasses,  is  seen  to  consist  of  four  distinct 
structures  called  its  Zones.  1.  The  Zona  Ossea  is  next  to  the  mo- 
diolus, and  is  composed  of  two  bony  laminae,  with  an  intermediate 
diploic  structure,  in  which  are  the  canals  for  transmitting  the  fila- 
ments of  the  portio  mollis  or  auditory  nerve.  2.  On  the  outer  side 
of  this  is,  the  Zona  Coriacea,  the  structure  of  which  is  cartilaginous. 

3.  The  Zona  Yesicularis,  said  to  contain  in  its  cells  a pellucid  fluid, 

4.  The  Zona  Membranacea,  which  is  probably  only  the  lining  mem- 
brane of  the  cochlea,  and  completes  the  lamina  spiralis  on  its  edge 
next  to  the  periphery  of  the  cochlea.  Some  very  respectable  anato- 
mists pass  over  this  minute  distinction  in  the  structure  of  the  septum, 
and  merely  divide  it  into  Zona  Ossea,  and  into  Zona  Mollis. 

Of  the  Membranous  Labyrinth * 

The  whole  internal  face  of  the  bony  Labyrinth  is  lined  by  a very 
delicate  and  vascular  membrane,  which  is  more  distinct  during  the 
early  periods  of  intra-uterine  life.  Besides  this,  there  is  a membra- 
nous labyrinth,  consisting  in  three  semi-circular  canals,  nearly  filling 
up  the  cavities,  and  having  the  same  shape  and  general  arrangement 
of  the  bony  canals ; and  in  two  sacs  contained  in  the  vestibule. 

The  Semicircular  Membranous  Canals  have  also  at  their  ends  the 
elliptical  enlargements  called  ampullae ; they  terminate  by  both  ex- 
tremities in  the  sac  of  the  superior  part  of  the  vestibule.  This  sac 
is  generally  called,  from  its  shape,  Sacculus  Ellipticus ; and  by  Scarpa, 
from  its  function,  the  Alveus  Communis.  In  front  of  the  Sacculus 
Ellipticus,  nearer  the  cochlea,  and  opposite  the  foramen  ovale,  is 
the  Sacculus  Sphericus;  it  is  a complete  bag,  having  no  communi- 
cation with  the  other,  or  with  the  membranous  canals.  Both  of  the 
sacs  adhere  to  the  vestibulum  at  their  posterior  parietes. 

The  sacs  of  the  vestibule  and  the  membranous  semicircular  canals 
are  filled  with  a very  fluid  transparent  liquid.  According  to  the  ob- 
servations of  M.  Ribes,  it  is  not  necessary  to  the  function  of  hearing 
that  this  fluid  should  be  so  abundant  as  to  distend  the  membranous 
labyrinth,  inasmuch  as  in  his  dissections  he  met  with  individuals  in 
whom  the  latter  was  only  half  filled,  and  yet  they  had  heard  very 
well.  He  also  met  with  similar  cases  in  which  the  fluid  was  abun- 
dant in  the  vestibulum,  but  deficient  in  the  canals,  and  the  reverse. 

* Anat.  Atlas,  Figs.  605  to  607,  inclusive. 


482 


NERVOUS  SYSTEM. 


Corresponding  observations  have  been  made  by  M.  Brugnone,  of 
Turin,*  where  he  had  adopted  the  precaution  of  previously  freezing 
the  bone,  so  that  none  of  the  fluid  could  be  said  to  have  been  lost 
by  accident.  From  the  frequency  with  which  this  deficiency  was 
observed,  his  opinion  seems  to  be  well  founded,  that  it  is  the  most 
natural  state  of  the  labyrinth. 

The  parietes  of  the  membranous  labyrinth  are  very  thin  and  trans- 
parent ; there  is  a very  loose  cellular  tissue  between  them  and  the 
bone,  and  they  are  susceptible  of  being  highly  coloured  by  injec- 
tion.! 

A fluid  of  the  same  character  with  the  preceding  also  fills  the 
scalse  of  the  cochlea,  and  extends  itself  into  the  bony  vestibulum 
and  the  bony  semicircular  canals  upon  the  outer  surface  of  the  mem- 
branous labyrinth. 

In  the  Sacculus  Ellipticus  are  found  numerous  small  crystalline 
pulverulent  masses  of  a calcarious  composition.  They  are  thought 
to  contribute  to  the  auditive  function  of  the  Labyrinth,  and  are  called 
Otoconites  ( otoconie)\  from  their  powdered  state  and  position  in  the 
ear,  in  contradistinction  to  the  term  Otolites  or  ear  atones  as  seen 
in  fishes  and  amphibia.  Huschke§  calls  them  the  auditive  crystals. 
Liebold  made  a singular  observation  concerning  them  in  the  bivalves 
and  snails,  to  wit,  that  during  the  life  of  the  animal  they  had  a re- 
markable motion.  ||  This  observation  has  been  confirmed  in  similar 
animals  by  Dr.  Leidy,  who  informed  me  that  the  motion  was  vibra- 
tile  and  centripetal  during  the  life  of  the  animal ; but  upon  life 
ceasing,  these  crystals  dispersed  and  then  remained  stationary. 

Of  the  Aqueducts  of  the  Ear. 

The  Aqueducts  ( Aqucedudus ) of  Cotunnius,  as  they  are  called, 
after  their  discoverer,  are  two  small  canals  which  go  through  the 
petrous  bone  from  the  labyrinth.  There  is  one  for  the  vestibule,  and 
another  for  the  cochlea. 

The  Aqueduct  of  the  Vestibulum  commences  in  the  latter  cavity 
somewhat  in  advance  of  the  common  orifice  of  the  tw7o  semicircular 
canals ; it  goes  inwards  and  opens  on  the  posterior  face  of  the  petrous 
bone,  behind  the  meatus  internus.  It  enlarges  gradually  in  its  course, 

* Mem.  de  Turin,  1805 — 1808.  t Anat.  Atlas,  Fig.  613. 

t Breschet.  Mem.  de  l’Acad.  Royale  de  Med.  Tom.  5. 

§ Traitd.  de  Splanclin.,  p.  812. 

II  Wagner’s  Physiol,  p.  532.  London  1844. 


THE  AQUEDUCTS  OF  THE  EAR. 


483 


which  causes  it  to  have  somewhat  of  a triangular  shape,  and  it  is 
lined  by  a continuation  of  the  dura  mater.  It  is  about  four  lines 
long. 

The  Aqueduct  of  the  Cochlea  commences  in  the  Scala  Tympani, 
near  the  foramen  rotundum,  and,  enlarging  in  its  course,  terminates 
on  the  under  surface  of  the  petrous  bone,  in  the  internal  margin  of 
the  jugular  fossa,  at  the  root  of  the  little  spine  which  separates  the 
eighth  pair  of  nerves  from  the  jugular  vein. 

The  anatomist*  from  whom  these  canals  were  named,  and  who 
first  described  them,  was  under  an  impression  that  the  fluid  of  the 
labyrinth  always  filled  it  completely ; and  that  without  a sort  of 
waste  gate  for  it  on  an  occasion,  the  vibration  of  the  stapes  would 
be  prevented  from  putting  the  fluid  in  motion,  and  consequently, 
hearing  must  cease.  These  canals,  the  existence  of  which  is  suffi- 
ciently obvious  in  many  subjects,  were,  therefore,  considered  by 
him  as  the  desired  avenues  for  the  discharge  of  the  superabundant 
fluid,  and  his  theory  and  descriptions  were  very  generally  adopted. 
Of  later  years,  the  investigation  of  this  subject  has  been  renewed  by 
MM.  Ribes  and  Brugnone,  and  their  observations  are  considered  by 
the  French  anatomists  to  have  proved  conclusively  the  error  into 
which  Cotunnius  and  others  have  fallen. 

In  regard  to  the  aqueduct  of  the  vestibule,  M.  Ribes  has  found 
it  only  in  three  instances  emptying  into  the  vestibule ; for  most 
commonly  it  leads,  after  a course  somewhat  tortuous,  into  the 
spongy  structure  of  the  petrous  bone,  at  the  posterior  part  of  the 
vestibule,  and  smaller  canals  diverge  from  it  in  different  directions. 
In  the  cases  where  it  was  connected  with  the  labyrinth,  it  was  so  by 
several  orifices  leading  into  the  vestibule,  and  into  the  posterior 
semicircular  canal.  He  has  not  found  this  canal  in  the  fcetus,  nor 
till  some  time  after  birth,  and  from  his  injections  he  believes  that,  in 
all  cases,  it  and  its  branches  are  only  intended  to  convey  blood  ves- 
sels throughout  the  petrous  bone  and  to  the  labyrinth. 

In  regard  to  the  supposed  aqueduct  of  the  cochlea,  M.  Ribes  has 
also  found  it  diverging  into  collateral  branches,  and  occupied  by 
blood  vessels,  which  are  distributed  to  the  spongy  structure  of  the 
petrous  bone,  and  to  the  tympanum. 

In  my  own  researches  on  this  point,  on  the  dried  bones,  the 
fcanals,  as  described  by  Cotunnius,  wrere  closed  at  the  labyrinth,  in 


* Dominici  Colunnii.  Anat.  Dissert,  de  Aquseduct.  Naples,  1761. 


484 


NERVOUS  SYSTEM. 


the  case  of  subjects  advanced  in  life ; but  in  the  middle  aged,  and 
in  infantile  specimens,  I have  been  more  successful  in  tracing  them 
fairly  into  the  labyrinth,  and  have  the  preparations  in  the  Wistar 
Museum.  At  the  same  time,  I think  it  much  more  probable  that 
they  only  contained  blood  vessels,  and  that  Cotunnius  was  in  error. 
Besides  these  vascular  canals,  M.  Ribes  has  described  some  others 
having  the  same  use. 


SECT.  IV. — OF  THE  NERVES  OF  THE  ORGAN  OF  HEARING.* 

The  Nerves  which  pass  through  the  petrous  bone,  and  are  either 
wholly  or  partially  spent  upon  the  organ  of  hearing,  come  from  three 
sources.  1.  The  Auditory  Nerve;  2.  The  Portio  Dura;  3.  The 
Trigeminus,  or  Fifth  Pair. 

The  Meatus  Auditorius  Internus  conducts  the  first  two,  and  has 
its  bottom  divided  by  a ridge  into  two  fossce,  of  which  the  upper 
one  is  the  smaller.  This  bottom  it  has  been  observed,  corresponds 
with  the  base  of  the  modiolus,  and  is  cribriform.  One  foramen, 
larger  than  any  of  the  others,  and  in  the  superior  fossa,  transmits  the 
portio  dura  or  facial  nerve  : all  the  others  are  occupied  by  the  fila- 
ments of  the  auditory  nerve. 

1.  The  Auditory  Nerve  divides  at  the  bottom  of  the  meatus  into 
fasciculi  of  filaments  ; one  of  which  penetrates  into  the  vestibulum 
through  the  foramina  behind  that  for  the  portio  dura,  and  is  distri- 
buted upon  the  sacculus  ellipticus,  and  upon  the  ampulla  of  the 
superior  and  of  the  exterior  membranous  canal ; other  filaments  get 
to  the  sacculus  sphericus;  and  a thirdflasciculus  of  filaments  is  dis- 
tributed to  the  ampulla  of  the  posterior  membranous  canal.  These 
several  filaments  are  said  to  preserve,  when  they  first  penetrate  into 
the  bony  labyrinth,  a fibrous  appearance,  and  are  interlaced ; they 
also  penetrate  the  parietes  of  the  membranous  labyrinth,  and  have 
their  extremities  bathed  in  its  fluid,  in  which  place  they  are  con- 
verted into  a soft  pulp,  resembling  mucus,  or  the  retina. 

Another  very  considerable  fasciculus  of  filaments  penetrates  into 
the  canals  of  the  modiolus,  and  enters  through  them  into  the  cavity 
of  the  cochlea,  along  the  Zona  Ossea,  and  between  its  tables  ; they 
terminate  also  by  a soft  pulp  on  the  internal  face  of  the  lining  mem- 


Anat.  Atlas,  Figs.  611,  612,  615. 


NERVES  OF  THE  ORGAN  OF  HEARING. 


485 


brane  of  the  cochlea.  One  of  these  filaments,  conspicuous  for  its 
size,  goes  through  the  central  canal  of  the  modiolus  and  terminates 
in  the  infundibulum.* 

2.  The  Facial  Nerve,  or  Portio  Dura,  is  only  connected  to  the 
organ  of  hearing  by  sending  a few  filaments  to  the  muscles  of  the 
bones  of  the  tympanum.  The  canal  of  the  petrous  bone,  through 
which  it  passes,  is  very  crooked ; beginning  at  the  larger  orifice  of 
the  meatus  internus  in  its  upper  fossa,  it  passes  outwards  until  it 
nearly  reaches  the  Vidian  foramen,  on  the  front  of  the  petrous  bone  ; 
it  then  turns  very  abruptly  backwards,  forming  an  angle,  and  is  con- 
tinued in  a circuit  around  the  superior  and  the  posterior  parietes  of 
the  tympanum,  till  it  terminates  in  the  stylo-mastoid  foramen.  Its 
course  is  marked  by  a ridge  projecting  into  the  tympanum,  above 
the  foramen  ovale,  and  passing  between  the  semicircular  canals 
and  the  cochlea.  This  canal  has  been  very  much  misnamed  by 
calling  it  the  aqueduct  of  Fallopius,  as  its  only  use  is  to  conduct 
nerves  and  blood  vessels.  It  is  lined  by  a delicate  fibrous  membrane 
between  which,  and  its  contained  parts,  there  is  so  little  adhesion, 
that  the  latter  may  be  drawn  out  entire. 

The  facial  nerve  is  joined  at  the  Vidian  foramen  by  the  Vidian 
nerve,  shortly  after  which  it  sends  a filament  to  the  tensor  tympani 
muscle. f As  it  passes  the  base  of  the  pyramid  it  detaches  another 
filament,  which  supplies  the  stapedius  muscle. 

Shortly  after  this,  it  is  abandoned  by  the  Vidian  nerve,  and  does 
not  give  off  any  more  branches  till  it  escapes  from  the  stylo-mastoid 
foramen  when  it  sends  off  a branch,  the  posterior  auricular  ( Auricu - 
laris  Posterior ,)  which  is  distributed  by  filaments,  some  of  which 
run  into  the  mastoid  process ; other  branches  mount  on  the  side  of 
this  process,  to  the  skin  which  covers  it,  and  to  the  occipital  muscle  : 
others  go  to  the  concha  of  the  ear,  being  spent  upon  its  skin,  upon 
the  posterior  auricular  muscle,  and  some  of  them,  penetrating  the 
pinna,  are  lost  upon  the  integuments  of  the  meatus  externus.  The 
trunk  of  the  facial  then  goes  to  its  destination  on  the  face. 

3.  The  Chorda  Tympani  or  Superficial  Petrous  Nerve,  is  a branch 
of  the  Pterygoid  branch  of  the  Trigeminus,  and  leaves  it  near  the 

* For  a knowledge  of  the  minute  distribution  of  the  auditory  nerve,  the  profes- 
sion is  signally  indebted  to  the  distinguished  Scarpa,  in  his  Disquisitiones  de  Auditu 
et  Olfactu. 

t The  tensor  tympani  is  also  supplied  by  a nerve  from  the  Third  Branch  of  the 
Trigeminus. 

Vol.  II.— 42 


4SG 


NERVOUS  SYSTEM. 


anterior  part  of  the  carotid  canal  of  the  petrous  bone.  It,  as  just 
mentioned,  under  the  name  of  Vidian  nerve,  joins  the  facial  nerve 
at  the  angle  of  the  canal  of  Fallopius,  and  continues  to  adhere 
closely  to  it,  almost  to  the  stylo  mastoid  foramen ; it  then  abandons 
the  facial  nerve  at  a very  acute  angle,  and  running  upwards  and  for- 
wards, gets  into  the  cavity  of  the  tympanum,  on  a level  with,  but  a 
line  or  two  exterior  to  the  pyramid.  It  then  crosses  the  tympanum 
nearly  horizontally,  between  the  long  crus  of  the  incus  and  the  handle 
of  the  malleus,  adhering  to  the  latter  so  as  to  be  affected  by  its  vi- 
brations. At  the  fore  part  of  the  tympanum,  it  anastomoses  with 
some  other  filaments  of  the  fifth  pair,  by  which  its  size  is  augmented, 
but  it  gives  no  branches  to  the  parts  contained  in  the  tympanum. 
It  then  issues  from  the  latter  cavity  through  the  glenoid  foramen,  and 
descending  a short  but  somewhat  variable  distance  along  the  ramus 
of  the  lower  jaw,  terminates  by  anastomosing  at  an  acute  angle  with 
the  lingual  branch  of  the  trigeminus. 

To  Mr.  John  Hunter  is  due  the  merit  of  having  traced  the  con- 
tinuity and  identity  of  the  Vidian  nerve,  with  the  chorda  tympani. 
The  continental  European  anatomists,  for  the  most  part,  seem  igno- 
rant of  his  observations,  and  give  a very  different  account  of  the 
matter.  Some  consider  it  to  arise  from  the  facial  at  its  angle,  and 
to  join  at  the  other  end  with  the  pterygoid  ; or  a reverse  origin  and 
termination : and  they  very  generally  agree  in  regarding  the  chorda 
tympani  as  a filament  from  the  facial,  just  before^the  latter  gets  out 
of  the  stylo-mastoid  foramen. 

The  Vidian  Nerve,  or  Superficial  Petrous,  also  traverses  the  tym- 
panum in  another  place.  Just  below  the  posterior  extremity  of  the 
Eustachian  Canal,  there  is  a small  foramen,  which  leads  upwards  to 
the  superior  surface  of  the- petrous  bone,  and  downwards  to  a small 
gutter  upon  the  promontory : this  gutter  is  converted  into  a canal 
that  opens  upon  the  under  surface  of  the  petrous  bone,  between  the 
carotid  canal  and  the  jugular  fossa.  Through  the  course  indicated, 
passes  a filament  from  the  superficial  petrous  nerve  : this  filament  is 
joined  by  another  detached  from  the  sympathetic  while  in  the  caro- 
tid canal,  and  the  two  communicate  at  the  base  of  the  cranium  with 
the  ganglion  of  the  glosso-pharyngeal  nerve.*  These  filaments 
were  discovered  by  Professor  Jacobson,  of  Copenhagen,  and  form 
what  is  now  called  the  Anastomosis  of  Jacobson. 

* Meckel,  Man.  D’Anat.,  vol.  iii.,  p.  174.  Jacobson,  Supplcm.  Act.  Hath.,  vol.  v. 
p.  292.  An.  1818. 


BOOH  IX. 


PART  IT. 

SPECIAL  ANATOMY  OF  THE  NERVES. 
CHAPTER  I. 

Of  the  Nerves  of  the  Encephalon. 

SECTION  i. 

The  course  and  distribution  of  the  first  pair,  or  the  olfactory 
nerves,  have  been  described  fully  in  the  account  of  the  brain  and 
nose. 

SECT.  II. — NERVUS  OPTICUS.* 

The  Optic  nerve,  as  mentioned  in  the  account  of  the  basis  of  the 
brain,  gets  into  the  orbit  by  the  optic  foramen,  and  is  there  entirely 
surrounded  by  the  origins  of  the  muscles  of  the  eye-ball.  It  then 
describes  a slight  curvature,  of  which  the  convexity  is  outwards,  and 
runs  forwards  for  an  inch,  when  it  penetrates  into  the  ball  of  the  eye, 
where  it  gives  origin  to  or  expands  into  the  retina.  Between  the 
muscles  and  it,  except  at  their  origins,  there  is  a mass  of  adipose 
matter. 


Anat.  Atlas,  Fig.  617. 


4SS 


NERVOUS  SYSTEM. 


SECT.  III. — NERVUS  MOTOR  OCULI. 

The  Nervus  Motor  Oculi,  or  third  Nerve  having  reached  from  the 
basis  of  the  brain  to  the  external  side  of  the  cavernous  sinus,  is 
placed  there  within  and  above  the  optic  nerve  and  the  sixth  pair;  it 
then  changes  its  direction,  and  penetrates  through  the  sphenoidal 
foramen  or  fissure  into  the  orbit,  on  the  outer  side  of  these  nerves, 
and  below  them. 

The  motor  oculi  divides,  in  the  sphenoidal  foramen,  into  two 
branches,  one  above  the  other.  The  first  crosses  over  the  optic 
nerve  and  the  nasal  branch  of  the  ophthalmic,  having  some  anas- 
tomoses with  the  latter,  and  then  distributes  its  filaments  upon  the 
iectus  superior  muscle  : some  of  them  also  penetrate  the  latter  to  get 
to  the  levator  palpebral  superioris.  The  second  branch  is  much  larger 
than  the  first.  It  passes  between  the  optic  nerve  and  the  rectus  in- 
ferior muscle,  and  is  subdivided  into  three  fasciculi : one  for  the  rectus 
interims  muscle  ; another  for  the  rectus  inferior  ; and  a third,  which 
is  the  longest  and  the  smallest,  for  the  obliquus  inferior  muscle.  The 
latter  fasciculus,  not  far  from  its  root,  gives  off  a filament,  which, 
going  along  the  external  margin  of  the  optic  nerve,  runs  into  the 
posterior  margin  of  the  lenticular  or  ophthalmic  ganglion,  and  is  its 
short  root. 

The  Lenticular  Ganglion  is  situated  on  the  outer  side  of  the  optic 
nerve,  in  the  orbit  of  the  eye,  and  is  about  a line  in  diameter,  being 
flattened.  Two  nerves  concur  to  form  it:  the  branch  just  alluded 
to,  from  the  motor  oculi,  and  one  from  the  ophthalmic  division  of 
the  trigeminus.  From  this  ganglion  arise  the  most  of  the  ciliary 
nerves ; which,  as  stated,  are  about  twenty  in  number,  and  go  to  the 
choroid  coat  of  the  eye  and  to  the  iris. 

SECT.  IV. — NERVUS  TROCHLEARIS. 

The  Nervus  Trochlearis,  or  fourth  Nerve  having  got  into  its 
canal  in  the  cavernous  sinus,  as  it  goes  along  the  internal  margin 
of  the  ophthalmic  nerve,  receives  there  a small  filament  from  it.* 

* Soemmering,  leones  Oculi  Humani. 


NERVUS  TRIGEMINUS. 


489 


It  then  rises  a little,  and  enters  the  orbit  at  the  internal  extremity 
of  the  sphenoidal  foramen ; and,  going  forwards,  next  to  the  perios- 
teum of  the  upper  part  of  the  orbit,  it  enters  into  the  superior  ob- 
lique muscle  of  the  eye,  near  its  middle,  and  is  distributed  upon 
it.  This  nerve  augments  in  volume  as  it  advances  towards  its. 
destination. 

SECT.  V. — OF  THE  NERVUS  MOTOR  EXTERNUS. 

The  Nervus  Motor  Externus,  or  sixth  Nerve,  having  got  into  the- 
cavernous  sinus,  is  placed  at  the  external  side  of  the  internal  caro- 
tid artery,  and  adheres  closely  to  it.  It  there  sends  off  one  or  more 
filaments,  which  follow  the  internal  carotid  artery  through  its  canal, 
and  anastomose  in  their  descent  with  a branch  of  the  pterygoid  nerve  : 
the  junction  of  these  two  forms  the  upper  end  of  the  great  sympa- 
thetic nerve,  and  runs- down  to  the  superior  cervical  ganglion  of  the 
sympathetic  in  two  or  more  filaments  generally.  The  sixth  nerve 
enters  the  orbit  through  the  sphenoid  foramen,  and  is  there  closely 
connected  with  the  nervus  Motor  oculi  and  the  Nasal  nerve.  It 
penetrates  into  the  substance  of  the  rectus  externus  muscle,  and  is 
entirely  distributed  upon  it ; with  the  exception  that  it  sometimes 
sends  a filament  to  the  ophthalmic  ganglion. 

SECT.  VI, — OF  THE  NERVUS  TRIGEMINUS,*' 

The  Trigeminus  or  Fifth  Nerve,  having  formed  the  ganglion  ot 
Gasser,  ( Pexus  Glangliformis ,)  on  the  side  of  the  petrous  bone, 
then  divides,  as  mentioned,  into  three  large  trunks,  the  foremost  of 
which  is  the  Ophthalmic  Nerve  : the  second  fasciculus  is  the  Su- 
perior Maxillary;  and  the  third  the  Inferior  Maxillary  Nerve. 

The  Ophthalmic  Nerve,  or  the  first  division  of  the  trigeminus,  is 
smaller  than  either  of  the  other  two,  and  comes  from  the  superior 
part  of  the  plexus-  gangliformis.  It  passes  along  the  external 
border  of  the  cavernous  sinus,  and  penetrates  the  orbit  through, 
the  sphenoidal  foramen.,  on  the  outer  side  of,  and  near  the  motor 
oculi. 

In  its  whole  course  it  is  united-  to  the  trochlearis  nerve  by  elosss 
* Amt.  Atlas,  Figs.  GI.8,  010 

42* 


490 


NERVOUS  SYSTEM. 


cellular  membrane,  and  does  not  give  off  any  ramifications  before 
it  reaches  the  orbit,  with  the  exception  of  the  filament  sent  to  the 
trochlearis  nerve.  While  engaged  in  the  sphenoidal  fissure  it 
separates  into  three  branches ; the  Nasal,  the  Lachrymal,  and  the 
Frontal. 

The  Nasal  branch  of  the  ophthalmic,  is  between  the  other  two 
in  size.  It  ascends  obliquely  above  the  optic  nerve  to  gain  the  in- 
ternal face  of  the  orbit  of  the  eye,  and  then  passes  forwards  just 
below  the  superior  oblique  muscle,  involved  in  a quantity  of  adi- 
pose matter.  Shortly  after  its  origin  the  nasal  nerve  detaches  a 
branch  {the  ramus  ciliaris)  which,  situated  at  the  external  margin 
of  the  optic  nerve,  runs  into  the  ophthalmic  or  lenticular  ganglion, 
and  constitutes  the  long  root ; it  then  sends  off  one  or  more  fila- 
ments, which,  without  communicating  with  this  ganglion,  penetrate 
into  the  eyeball,  and  are  amongst  the  ciliary  nerves  which  have  been 
described. 

The  nasal  nerve  continuing  to  pass  forward  along  the  internal 
paries  of  the  orbit,  when  it  reaches  the  anterior  internal  orbitary 
foramen,  detaches  through  it  the  Internal  nasal  or  ethmoidal  branch, 
which,  thus  getting  into  the  cavity  of  the  cranium,  goes  along  side 
of  the  crista  galli,  and  passes  into  the  nose  through  the  foremost 
hole  of  the  cribriform  plate  ; — then  descends  along  the  anterior  part 
of  the  nose,  on  the  outer  side  of  the  Schneiderian  membrane,  and 
is  spent  by  ramifications  upon  the  contiguous  portions  of  the  latter : 
some  of  the  terminating  branches  reach  the  tip  of  the  nose  and  the 
alae.* 

The  nasal  nerve,  after  the  ethmoidal  branch  is  sent  off,  is  fre- 
quently called  External  nasal , or  nervus  infra-trochlearis.  It  con- 
tinues to  advance  along  the  under  margin  of  the  trochlearis  muscle 
and  gets  to  the  trochlea,  near  which  it  divides  into  an  upper  and  an 
under  ramuscule;  from  them  filaments  proceed  to  the  upper  and  under 
eyelids,  to  the  lachrymal  sac,  the  lachrymal  caruncle,  the  tunica  con- 
junctiva, and  the  muscles  on  the  root  of  the  nose.  These  filaments 
anastomose  with  the  terminating  branches  of  the  frontal  nerve,  the 
facial,  and  the  infra-orbitary.  According  to  Dr.  G.  Trasmondi,f  of 

* Sec  Nerves  of  the  Nose. 

t Intorno  la  scoperta  di  due  nervi  del  Occliio  umano  ragguaglio  del  Dr.  Giuseppe 
Trasmondi,  Professor®  di  Anatomia  Practica  u.el  vcn.  ospidale  della  Consolazione. 
Roma,  1823. 


NERVUS  TRIGEMINUS. 


491 


Rome,  two  filaments  may  be  traced  very  distinctly  from  the  external 
nasal  nerve  to  the  tensor  tarsi  muscle  of  the  lachrymal  sac.  They 
adhere  to  the  muscle  by  means  of  cellular  tissue,  and  pass  on  to  its 
bifurcated  extremities  and  to  the  puncta  lachrymalia. 

The  Frontal  Nerve,  is  the  largest  of  the  three  branches  of  the  oph- 
thalmic. It  proceeds  forward  between  the  levator  palpebrse  supe- 
rior^ and  the  contiguous  part  of  the  orbit,  and  in  this  course  is 
divided  into  two  branches,  the  internal  and  the  external  frontal 
nerve.  The  former  approaches  the  trochlea  of  the  upper  oblique 
muscle,  and  detaches  a filament  to  join  with  one  from  the  Nasal 
nerve.  Other  filaments  are  detached  to  the  upper  eyelid,  some  of 
which  anastomose  with  filaments  from  the  Lachrymal  nerve.  The 
internal  branch  of  the  frontal  then  issues  from  the  orbit  close  by  the 
trochlea,  and,  in  ascending,  is  lost  upon  the  occipito-frontalis,  the 
corrugator  supercilii,  and  the  orbicularis  muscle.  The  external 
branch  of  the  frontal  issues  from  the  orbit,  through  the  supra-orbitary 
foramen.  It  quickly  detaches  a filament,  which  goes  outwardly  to 
anastomose  with  the  facial ; the  remaining  part  of  the  nerve  is  dis- 
tributed to  the  occipito-frontalis,  to  the  corrugator  supercilii,  to  the 
integuments  of  the  forehead,  and  to  the  scalp.  This  distribution,  ac- 
cording to  Bichat,  is  best  followed  by  detaching  the  skin,  the  muscles, 
and  the  periosteum  from  the  cranium,  from  behind  forwards  as  far 
as  the  orbit. 

The  Lachrymal  Branch  of  the  ophthalmic  nerve  goes  forwards 
along  the  external  side  of  the  orbit  near  the  superior  margin  of  the 
rectus  externus  muscle.  In  this  course  it  sends  offa  filament  through 
the  spheno-maxillary  fissure  which  unites  with  one  from  the  second 
branch  of  the  fifth  pair ; it  afterwards  sends  off  another  filament, 
which,  passing  through  a foramen  in  the  malar  bone,  anastomoses 
with  a filament  of  the  facial  nerve.  What  remains  of  the  lachrymal 
nerve  is  then  distributed  by  several  filaments  upon  the  lachrymal 
gland,  the  upper  eyelid  and  some  of  them  reach  the  conjunctiva. 

Second  Branch  of  the  Trigeminus. 

The  Second  Branch  of  the  Fifth  Nerve,  ( JVervus  Maxillaris  Su- 
perior,) arising  from  the  middle  of  the  plexus  gangliformis,  or  gan- 


492 


NERVOUS  SYSTEM. 


glion  of  Gasser,  and  also,  in  part,  from  the  common  trunk  formed 
from  the  anterior  and  posterior  roots-  of  the  trigeminus,  gets  from  the 
cranium  through  the  foramen  rotundum  of  the  sphenoid  bone. 
While  still  in  the  cranium  it  sometimes  forms  an  anastomosis,  de*- 
scribed  by  Laumonier,  with  the  beginning  of  the  sympathetic  nerve, 
but  generally  it  does  not  detach  any  filament,  till  it  reaches  the 
pterygo-maxillary  fossa. 

At  a short  distance  after  its  exit  from  the  cranium,  it  gives  off 
a small  filament,  the  Nervus  Subcutaneus  Make,  which  ascends 
into  the  orbit  through  the  spheno-maxillary  fissure,  and  then  divides. 
One  of  the  branches,  the  malar,  anastomoses  with  the  lachrymal 
nerve,  and  leaves  filaments  with  the  lachrymal  gland  ; it  then  gets, 
by  one  or  more  filaments,  through  the  holes  of  the  malar  bone  to 
the  face,  and  terminates  on  the  orbicularis  muscle  and  the  skin  of 
the  cheek,  anastomosing  with  the  extremities  of  the  facial  nerve. 
The  other  branch,  the  temporal,  gets  into  the  temporal  fossa  by  pene- 
trating the  internal  part  of  the  malar  bone,  and,  having  anastomosed 
with  a branch  of  the  inferior  maxillary  nerve,  it  goes  outwards  and 
backwards,  becomes  superficial  by  penetrating  the  temporal  apo- 
neurosis, and  terminates  on  the  integuments  of  the  temple,  anasto- 
mosing there  with  the  branches  of  the  facial  nerve. 

The  superior  maxillary  then  divides  into  two  trunks  much  larger 
than  the  preceding,  and  of  a volume  nearly  equal ; the  Infra-Orbital 
and  the  Pterygo-Palatine. 

The  Infra-Orbital  ( JVervus  Infra- Orbitalis)  passes  forwards,  with 
a slight  ascent,  to  the  posterior  part  of  the  orbit,  and  enters  the  in- 
fra-orbitar  canal.  As  it  is  about  engaging  in  the  latter,  it  detaches 
a considerable  branch,  the  Posterior  Dental.  This  branch  descends 
a little  distance,  externally,  along  the  posterior  paries  of  the  max- 
illary sinus,  then  penetrates  into  the  cavity  of  the  latter.  It  ter- 
minates by  filaments,  some  of  which  supply  the  lining  membrane  of 
the  antrum  ; others  pass  through  the  little  canals  leading  to  the  three 
large  grinders,  and  enter  the  roots  of  the  latter;  others  go  to  the 
corresponding  gums.  One  branch  goes  along  the  outer  side  of  the 
sinus  to  anastomose  with  the  anterior  dental  nerve.  The  posterior 
dental,  before  it  enters  the  bone,  also  detaches  a branch  of  some 
size,  which  winds  around  the  tuberosity  of  the  maxillary  bone,  and 
is  spent  upon  the  buccinator  muscle  and  upon  the  gums. 

The  infra- orbitary  nerve  afterwards,  in  its  course  through  the 
eanal,  sends  off  the  Anterior  dental  nerves  from,  one  or  more  roots,. 


NERVUS  TRIGEMINUS. 


493 


Some  of  them  detach  fibres  to  the  mucous  membrane  of  the  nose, 
where  it  covers  the  anterior  part  of  the  inferior  turbinated  bone. 
With  this  exception,  they  are  distributed,  through  their  appropriate 
canals  in  the  bone,  to  the  incisor  and  canine  teeth,  and  to  the  cor- 
responding gums.  The  small  molar  teeth  are  most  frequently  sup- 
plied by  an  union  of  filaments,  from  the  anterior  and  posterior  den- 
tal nerves. 

The  infra-orbitar  nerve,  on  issuing  from  the  infra-orbitar  foramen, 
is  most  frequently  found  already  divided  into  several  fasciculi,  which 
may  be  classed  into  superior  and  into  inferior.  The  former,  called 
Palpebral,  radiate,  externally  and  internally,  into  filaments  which 
supply  the  lower  eyelid.  One  of  these  filaments  may  be  traced  to 
the  end  of  the  nose,  where  it  anastomoses  with  the  internal  nasal 
branch  of  the  ophthalmic ; another,  which  terminates  about  the  internal 
angle  of  the  eye,  anastomoses  there  with  the  external  nasal  nerve. 
Others  of  its  terminating  filaments  anastomose  with  the  extremities 
of  the  facial  nerve  on  the  eyelid.  The  inferior  fasciculi  are  more 
numerous  and  large  than  the  superior.  They  descend  upon  the  face 
covered  by  the  levator  muscles  of  the  upper  lip,  and  from  their  dis- 
tribution are  called  Labial.  The  most  internal  of  these  fasciculi 
terminate  on  the  skin,  the  muscles,  and  the  beginning  of  the  mucous 
membrane  of  the  nose,  where  they  anastomose  with  the  extremities 
of  the  internal  nasal  nerve.  The  middle  fasciculi  go  to  the  muscles 
of  the  upper  lip  and  the  skin  of  the  latter,  and  to  its  mucous  glands. 
The  external  fasciculi  go  to  the  zygomatic  muscles  and  to  the  con- 
tiguous skin.  All  the  foregoing  branches  of  the  infra-orbitar  nerve 
anastomose  with  the  extremities  of  the  facial,  and  are  so  minutely 
distributed  to  the  skin  and  muscles  of  the  face,  that  it  would  require 
a very  protracted  description  to  point  them  out  particularly. 

The  Pterygo-palatine  Nerve  ( JYervus  Pterygo-palatinus ) descends, 
as  a single  or  a double  trunk,,  from  its  root  to  the  outside  of  the 
spheno-palatine  foramen,  and  there  forms  the  ganglion  of  Meckel,* 
or  the  spheno-palatine  ganglion,  the  existence  of  which  is  not  con- 
stant. From  this  ganglion,  or  from  the  nerve  itself  proceed  several 
blanches. 

A filament,  described  by  Bock,  is  detached  from  it,  which  enters 


Discovered5by  Merkel,  1749. 


494 


NERVOUS  SYSTEM. 


into  the  sphenoidal  sinus  to  be  distributed  on  its  lining  membrane, 
and  sometimes  to  anastomose  with  the  motor  externus  oculi. 

Then  arise  the  Spheno-palatine  branches,  which  enter  the  nose 
through  the  spheno-palatine  foramen,  and  are  distributed  upon  the 
mucous  membrane  of  its  septum  and  turbinated  portions,  after  the 
manner  described  in  the  account  of  the  nose. 

The  Vidian  or  Pterygoid  Nerve  ( JYervus  Vidianus , recurrens , 
pterygoideus)  arises  from  the  inferior  part  of  the  ganglion,  and  is  a 
recurrent  branch,  which  goes  backwards  through  the  .pterygoid  fora- 
men of  the  sphenoid  bone.  From  it  there  arise  some  filaments, 
which  get  to  the  mucous  membrane  about  the  anterior  orifice  of  the 
Eustachian  Tube,  either  through  the  spheno-palatine  foramen,  or  by 
small  foramina  in  the  pterygoid  process  of  the  sphenoid  bone.  They 
are  sometimes  united  into  a single  trunk,  called  pharyngeal,  by  Bock. 
The  Vidian  nerve,  while  still  in  its  canal,  then  divides  into  two  trunks, 
the  superficial,  and  the  deep  petrous. 

The  Superficial  Petrous  (JYervus  Petrosus  Superficial^ ) traverses 
the  cartilaginous  matter  at  the  point  of  the  petrous  bone,  in  the  an- 
terior foramen  lacerum  of  the  basis  of  the  cranium,  gets  there  into 
the  cavity  of  the  latter,  continues  its  progress  backwards  on  the 
superior  face  of  the  petrous  bone,  in  a gutter  marked  on  the  bone, 
and  disappears  through  the  Vidian  foramen.  It,  in  a short  space, 
reaches  the  aqueduct  of  Fallopius,  and  continues  to  adhere  to  the 
facial  nerve  till  the  latter  almost  reaches  the  stylo-mastoid  foramen: 
it  then  abandons  the  facial  nerve,  and,  as  mentioned  in  the  account 
of  the  ear,  traverses  the  tympanum  under  the  name  of  chorda  tym- 
pani ; and,  finally,  emerging  at  the  glenoid  foramen,  it  run§  to  asso- 
ciate itself  with  the  lingual  branch  of  the  trigeminus.  The  superficial 
petrous,  in  the  early  part  of  its  course,  at  the  point  of  the  petrous 
bone,  detaches  one  or  more  filaments  to  the  sympathetic  in  the 
carotid  canal. 

The  Deep  Petrous  ( JYervus  Petrosus  Profundus ) is  larger  than 
the  other.  It  also  penetrates  through  the  cartilaginous  matter  at  the 
point  of  the  petrous  bone,  and  enters  the  cavity  of  the  cranium  under 
the  dura  mater.  It  then  advances  to  the  internal  carotid  artery,  and 
anastomoses  there  with  a filament  from  the  motor  externus  or  sixth 


NERVUS  TRIGEMINUS. 


495 


nerve.  This  anastomosis  as  stated  is  commonly  called  the  beginning 
of  the  sympathetic  nerve. 

The  Palatine  Nerve  ( JYervus  Palntinus ) proceeds  from  the  inferior 
part  of  the  ganglion  of  Meckel,  and  gets  to  the  soft  palate  of  the 
mouth  through  the  posterior  palatine  foramen.  In  this  course,  it 
detaches  several  filaments  to  the  Schneiderian  membrane,  which 
reach  it  either  through  the  spheno-palatine  foramen,  or  by  perforating 
the  nasal  lamella'  of  the  palate  bone.  These  are  described  in  the 
account  of  the  nose. 

The  trunk  of  the  palatine  nerve,  having  reached  the  roof  of  the 
mouth,  bends  forwards,  and  is  divided  into  many  filaments,  some 
of  which  are  distributed  along  the  gums  of  the  upper  jaw,  others  are 
distributed  on  the  lining  membrane  of  the  hard  palate  and  upon  its 
mucous  glands. 

There  are  twTo  other  nerves,  which  arise  either  immediately  from 
the  palatine,  or  from  the  ganglion  of  Meckel,  and  go  to  supply  the 
soft  palate.  They  are  called  the  smaller  palatine.  One  of  them, 
having  proceeded  for  a short  distance  in  the  posterior  palatine  canal, 
departs  from  it  in  a little  canal  of  its  own,  wdiich  opens  behind  the 
hook  of  the  internal  pterygoid  process.  It  then  radiates  into  fila- 
ments, which  supply  the  tonsil  gland  and  the  muscular  and  mem- 
branous structure  of  the  soft  palate.  The  other  smaller  palatine  also 
traverses,  after  the  same  manner,  its  own  canal,  and  is  likewise  dis- 
tributed to  the  tonsil  gland  and  to  the  soft  palate. 

Third  Branch  of  the  Trigeminus. 

The  Third  Branch  of  the  Trigeminus  ( JYervus  Infra-maxillaris ) is 
the  largest  of  the  three.  It  arises  from  the  posterior  inferior  part  of 
the  ganglion  of  Gasser,  and  having  anastomosed  with  the  cavernous 
ganglion  of  the  sympathetic  nerve  by  filaments,  which  are  not  con- 
stant, it  emerges  from  the  cranium  through  the  foramen  ovale  of  the 
sphenoid  bone.  A portion  of  this  branch,  as  mentioned,  does  not 
enter  into  the  composition  of  the  ganglion  of  Gasser,  but  proceeds 
immediately  from  the  pons  varolii. 

The  inferior  maxillary  nerve,  at  its  exit  from  the  foramen  ovale, 
is  covered  by  the  pterygoideus  externus  muscle,  and  commonly 
divides  there  into  two  branches,  one  anterior  and  the  other  poste- 


496 


NERVOUS  SYSTEM. 


rior  or  else  sends  off  two  sets  of  branches — the  first  for  the  mus- 
cles of  mastication — and  the  second  set  for  the  lower  jaw  and 
tongue. 

The  Anterior  Branch,  or  set,  which  is  much  smaller  than  the  other, 
radiates  into  five  fasciculi;  the  masseter  nerve;  the  two  temporal  ; 
the  buccal ; and  the  pterygoid. 

a.  The  Masseter  Nerve  is  directed  horizontally  outwards  and  back- 
wards, along  the  external  margin  of  the  pterygoideus  externus,  and 
in  front  of  the  temporo-maxillary  articulation : it  leaves  some  fila- 
ments with  the  latter,  and  then  passing  between  the  insertion  of  the 
temporal  and  of  the  external  pterygoid  muscle,  over  the  concave 
edge  of  the  hone,  between  the  condyle  and  the  coronoid  process  of 
the  lower  jaw,  it  penetrates  into  the  substance  of  the  masseter  muscle, 
and  is  distributed  through  it. 

b.  The  two  Temporal  branches  arise  by  a common  fasciculus,  but 
sometimes  differently.  They 'pass  outwards,  horizontally,  between 
the  external  pterygoid  muscle  and  zygomatic  fossa.  They  then 
ascend  on  the  side  of  the  temporal  bone,  between  it  and  the  temporal 
muscle,  and  are  distributed  through  the  latter  by  a great  number  of 
filaments.  Some  of  these  filaments  penetrate  the  aponeurosis,  to 
anastomose  with  the  superficial  temporal  nerves.  And  one  of  them 
anastomoses  with  the  Temporal  Branch  of  the  Subcutaneus  Malse,  in 
the  temporal  fossa. 

c.  The  Buccal  Branch  is  the  largest  of  the  five.  It  advances  be- 
tween the  pterygoid  muscles,  to  which  it  furnishes  a few'  filaments, 
and  then  descends  between  the  temporal  and  external  pterygoid 
muscle  to  the  posterior  part  of  the  buccinator.  It  is  principally  dis- 
tributed on  the  latter,  upon  the  buccal  glands,  and  the  corresponding 
part  of  the  lining  membrane  of  the  mouth.  Some  of  its  branches 
advance  under  the  integuments  of  the  face,  as  far  as  the  commissure 
of  the  lips  to  the  muscles  there,  and  anastomose  with  the  facial 
nerve. 

d.  The  Pterygoid  Branch  is  the  smallest,  and  is  distributed  prin- 
cipally on  the  internal  pterygoid  muscle. 

The  Posterior  Branch  of  the  inferior  maxillary  nerve  is  so  large, 
that  it  looks  like  a continuation  of  the  trunk.  It  is  divided  into  the 
superficial  temporal,  the  inferior  dental,  and  the  lingual  nerve. 

a.  The  Superficial  Temporal  Branch  is  formed  by  an  union  of  two 
fasciculi,  between  which  passes  the  middle  artery  of  the  dura  mater  ; 


NERVPS  TRIGEMINUS. 


497 


the  inferior  of  these  fasciculi  comes  from  the  inferior  dental  nerve. 
The  nerve  is  directed  outwards,  and  winds  horizontally  around  the 
posterior  face  of  the  neck  of  the  condyle  of  the  lower  jaw,  between 
it  and  the  meatus  auditorius  externus.  It  is  there  divided  into  several 
small  fasciculi,  two  or  three  of  which  penetrate  into  the  substance  of 
the  parotid  gland,  and  anastomose  with  the  facial  nerve  or  its  rami- 
fications; one  or  two  others  go  backwards,  penetrate  between  the 
bony  and  the  cartilaginous  meatus  to  the  auditory  canal,  and  are 
dispersed  by  fine  filaments  upon  the  concha,  and  the  meatus  ex^ 
ternus.  According  to  Bock,  one  of  these  filaments  supplies  the 
membrane  of  the  tympanum,  and  also  anastomoses  with  the  chorda 
tympani.  Another  branch  of  the  superficial  temporal,  which  is  the 
largest  of  any,  traverses  the  parotid  gland,  and  thereby  becomes  super- 
ficial, just  in  front  of  the  external  ear.  It  then  divides  into  filaments, 
which  follow  the  course  of  the  superficial  temporal  artery,  and  thereby 
supply  the  middle  part  of  the  integuments  on  the  side  of  the  head. 
It  anastomoses  with  the  filaments  of  the  frontal  nerve,  and  with  those 
of  the  occipital. 

b.  The  Inferior  Dental  Nerve  is  placed  between  the  other  two 
branches,  and  exceeds  them  in  size.  It  descends  between  the  two 
pterygoid  muscles,  towards  the  posterior  mental  foramen.  Just 
above  the  latter  it  detaches  a small  branch,  the  Mylo-Hyoid,  which 
occupies  the  small  gutter  on  the  bone  leading  downward  from  the 
posterior  mental  foramen.  This  branch  sends  a filament  to  the  sub- 
maxillary  gland,  then  passes  between  the  anterior  belly  of  the  digas- 
tric muscle,  and  the  mylo-hyoideus,  to  both  of  which  it  gives  fila- 
ments; and  finally  winding  over  the  base  of  the  lower  jaw  in  front, 
it  is  lost  upon  the  muscles  of  the  chin* 

The  inferior  dental  nerve  then  enters  the  posterior  mental  fora- 
men, and  divides  into  two  branches,  which  run  parallel  with  one 
another  through  the  canal  in  the  middle  of  the  spongy  structure  of 
the  bone,  and  send  a great  number  of  anastomotic  filaments  to  each 
other.  One  of  the  branches,  the  dental,  properly  speaking,  as  it 
passes  along  the  ends  of  the  roots  of  the  teeth,  detaches  a fila- 
ment to  each  root,  from  the  last  grinder  to  the  first  incisor  tooth 
inclusively  : it  also  sends  a filament  to  the  gum  intermediate  to  every 
two  teeth.  All  of  these  filaments  arise  from  the  dental  nerve,  at 
places  behind  the  points  of  destination ; so  that  they  have,  before 
reaching  the  latter,  to  run  forwards  and  upwards  through  little  canals 
in  the  cellular  structure  of  the  bone. 

Vol.  II.— 43 


498 


NERVOUS  SYSTEM. 


The  other  branch  of  the  inferior  dental  nerve  is  the  mental ; it  does 
does  not  advance  so  far  forward  in  the  bone  as  the  preceding,  but 
issues  from  it  at  the  anterior  mental  foramen,  and  immediately  is 
divided  into  two  fasciculi,  the  inferior  labial  nerves.  The  internal 
fasciculus  is  distributed  by  filaments  upon  the  muscles  of  the  chin 
and  lower  lip,  the  contiguous  lining  membrane  of  the  mouth  and 
the  labial  glands.  The  external  fasciculus  rises  upwards  and  is 
distributed  on  the  muscular  structure,  about  the  under  part  of  the 
commissure  of  the  lip,  and  to  the  contiguous  lining  membrane  and 
glands  of  the  mouth; 

c.  The  Lingual  Nerve  descends  in  company  with  the  inferior 
dental,  but  in  advance  of  it,  and  diverging  slightly.  While  between 
the  two  pterygoid  muscles  it  receives  the  chorda  tympani  at  a 
very  acute  angle.  It  then  passes  towards  the  side  of  the  root  of  the 
tongue,  deeply  concealed  by  the  angle  of  the  lower  jaw,  and  above 
the  submaxillary  gland,  to  which  it  gives  some  considerable  fila- 
ments. 

A ganglion  called  the  Submaxillary , is  formed  here  by  one  or 
more  filaments  of  the  lingual  nerve,  and  from  this  ganglion  proceed 
filaments  to  the  submaxillary  gland. 

The  Submaxillary  Ganglion  is  so  named  from  being  placed  upon 
the  submaxillary  gland.  It  is  very  small  and  is  considered  by  some 
to  be  derived  from  the  Chorda  Tympani,  which  they  say,  after  join- 
ing the  gustatory  nerve,  leaves  it  and  unites  to  or  forms  this  gan- 
glion, with  the  assistance  of  some  two  or  more  filaments  from  the 
gustatory  nerve,  and  one  or  two  from  the  cervical  portion  of  the 
Sympathetic.  The  ganglion  also  detaches  forwards  filaments  to 
join  the  gustatory  nerve,  and  some  in  company  also  with  the  duct  of 
the  submaxillary  gland. 

The  lingual  nerve  then  proceeds  forwards  between  the  mylo-hy- 
oideus  and  the  hyo-glossus  muscle,  and  between  the  sublingual  gland 
and  the  latter,  having  in  front  of  it  the  excretory  duct  of  the  sub- 
maxillary gland;  It  anastomoses  frequently  with  the  hypo-glossal 
nerve,  sends  several  filaments  to  the  lining  membrane  of  the  mouth, 
below  the  tongue,  and  to  the  sublingual  gland.  It  then  divides,  or 
radiates,  into  seven  or  eight  fasciculi,  which  run  upwards  and  for- 
wards on  the  side  of  the  stylo-glossus  muscle,  and  the  genio- 
hyo-glossus,  and  are  finally  spent  by  very  fine  filaments  pene- 
trating into  the  structure  of  the  papillae,  on  the  upper  surface  of  the 
tongue; 


NERVUS  FACIALIS. 


499 


The  third  branch  of  the  trigeminus,  according  to  Dr.  Arnold  of 
Heidelburg,  also  forms,  by  several  filaments,  a ganglion  called  Otic , 
near  the  foramen  ovale.  This  ganglion  is  below  the  spinous  pro- 
cess of  the  sphenoid  bone,  and  sends  off  several  filaments  : one  con- 
tributes to  the  nervous  anastomosis  of  Jacobson,*  which  connects  the 
superficial  petrous,  sympathetic,  and  glosso-pharyngeal  nerves : 
another  filament  passes  to  the  tensor  tympani,  and  is  distributed 
upon  it.  Other  filaments  join  the  superficial  temporal  nerve : that 
part  of  it  which  supplies  the  membrana  tympani.  There  is  also  an 
anastomosis  with  the  portio  mollis. f 


SECT.  VII. NERVUS  FACIALIS. f 

The  Facial  Nerve  ( JYervus  Facialis ; portio  dura  sepiimi  ; par  sep- 
timum ) having  gained  the  meatus  auditorius  internus,  passes  in  front 
of  the  auditory  nerve  into  the  canal  of  Fallopius,  arid  winding 
through  it,  around  the  tympanum,  it  emerges  at  the  stylo-mastoid 
foramen,  having  sent  in  this  course  one  or  more  filaments  to  the 
muscles  of  the  little  bones  of  the  tympanum. 

Afterwards  the  facial  nerve  gives  off  several  branches,  which  are 
distributed  as  follows 

a.  The  Posterior  Auricular  ( Auriculans  Posterior ) arises  near  the 
stylo-mastoid  foramen,  as  stated  in  the  account  of  the  Nerves  of  the 
Ear ; and  having  sent  several  filaments  into  the  mastoid  process,  it 
winds  over  the  anterior  face  of  the  base  of  the  latter,  and  divides 
into  two  fasciculi.  The  anterior  is  distributed  in  filaments  upon  the 
back  of  the  external  ear,  the  cartilaginous  meatus,  and  the  posterior 
auris  muscle;  the  posterior  ascends  upon  the  mastoid  portion  of  the 
temporal  bone  to  the  posterior  belly  of  the  occipito-frontalis  muscle, 
and  is  spent  by  filaments  to  the  latter,  and  to  the  corresponding  in- 
teguments, anastomosing  likewise  with  ramifications  of  the  occipital 
nerve. 

b.  The  facial  nerve  then  detaches  filaments  to  the  muscles  of  the 
styloid  process,  and  to  the  posterior  belly  of  the  digastric  muscle.  It 
also  sends  filaments  of  anastomosis  to  the  superior  part  of  the  sym- 

* This  nervous  anastomosis  is  described,  page  486,  article  Vidian  Nerve, 
t Am.  Med.  Jour.,  vol.  v.,  p.  192. 
t Anal.  Atlas,  Fig.  G20. 


500 


NERVOUS  SYSTEM. 


pathetic  nerve  ; to  the  cutaneous  cervical ; and  to  ramifications 
of  the  glosso-pharyngeal,  of  the  pneumo-gastric,  and  of  the  acces- 
sory. 

The  facial  nerve,  having  given  off  the  foregoing  filaments  and 
branches,  penetrates  downwards  and  forwards  into  the  substance  of 
the  parotid  gland,  where  it  is  divided  into  a number  of  branches, 
varying  from  two  to  five,  which  form  a plexus  by  their  anastomoses. 
This  plexus  is  re-enforced,  as  mentioned,  by  branches  from  the  su- 
perficial temporal  of  the  inferior  maxillary,  which  wind  around  the 
neck  of  the  lower  jaw.  It  is  then  distributed  to  the  side  of  the  face 
in  radiating  clusters  or  columns  of  filaments,  called  the  Temporo- 
Facial,  the  Buccal,  and  the  Cervico-Facial. 

The  Temporo-Facial  Nerves,  or  Branches,  are  hid,  for  some  dis- 
tance, in  the  upper  part  of  the  parotid  gland,  which  they  traverse 
below  the  neck  of  the  lower  jaw.  They  divide  into  filaments,  some 
of’  which  go  to  the  temple,  and  others  to  the  cheek.  The  temporal 
branches  are  commonly  two  or  three  in  number;  they  leave  filaments 
with  the  parotid  gland,  mount  over  the  zygoma,  and  are  distributed 
to  the  anterior  auris  muscle,  to  the  outer  section  of  the  orbicularis 
palpebrarum,  and  to  the  integuments  of  the  temple  ; they  anasto- 
mose in  their  distribution  with  each  other,  with  the  superficial  and 
deep  temporal  branches  of  the  inferior  maxillary  nerve,  and  with  the 
frontal  and  lachrymal  branches  of  the  ophthalmic.  The  malar 
branches  are  primitively,  also  two  or  three  in  number : they  cross 
the  malar  bone,  dividing,  subdividing,  and  anastomosing  again,  and 
are  spent  upon  the  integuments  and  muscles  of  this  part  of  the  face. 
They  also  anastomose  with  filaments  of  the  lachrymal  nerve,  and 
with  those  of  the  infra-orbitar  nerve. 

The  Buccal  Branches  are'  three  in  number,  sometimes  two  only  ; 
and  pass  across  the  masseter  muscle  under  the  skin.  The  superior 
anastomoses  with  the  temporo-facial,  and  the  inferior  with  the  cer- 
vico-facial.  The  buccal  branches  supply  the  skin  and  muscles  of 
the  face  intermediate  to  the  eye  and  to  the  lower  lip.  The  numerous 
filaments  into  which  they  divide  anastomose  frequently  with  each  other, 
and  with  the  branches  of  the  fifth  pair,,  which  appear  about  the  same 
parts,  as  the  external  and  internal  nasal  nerve,  the  infra-orbitar,  and 
so  on.  The  middle  buccal  is  parallel  with  the  duct  of  the  parotid 
gland,  and  adheres  to  it. 

The  Cervico-Facial  Branch  descends  in  the  substance  of  the 
parotid  gland,  behind  the  ramus  of  the  lower  jaw;  when  it  reaches 


NERVUS  HYPOGLOSSUS. 


501 


the  angle  of  the  latter  it  goes  obliquely  forwards,  beneath  the  pla~ 
tysma  myodes  muscle.  Though  it  sends  off  many  fasciculi,  they 
may  be  referred  to  two  divisions,  a superior  and  an  inferior.  The 
first  crosses  the  inferior  part  of  the  masseter  muscle,  and  may  be 
traced  in  its  numerous  distribution  of  filaments,  to  the  integuments 
and  muscles  lying  upon  the  body  of  the  lower  jaw.  These  filaments 
anastomose  with  each  other,  and  with  the  mental  branches  of  the  inferior 
dental  nerve.  The  inferior  division  supplies  the  skin  and  the  pla- 
tysma  myodes  muscle  on  the  upper  part  of  the  neck,  along  the  base 
of  the  lower  jaw.  Its  filaments  are  joined  by  several  coming  from 
the  anterior  fasciculus  of  the  third  cervical  nerve. 

The  anastomoses  of  the  facial  nerve,  derived  from  its  own  branches 
and  from  those  of  the  trigeminus,  which  reach  the  face,  are  entirely 
too  numerous  for  a detailed  description  of  them;  it,  indeed,  appears 
unnecessary  to  extend  the  latter  beyond  a certain  point.  The  most 
satisfactory  account  has  been  published  by  Meckel.* 


SECT.  VIII. — NERVUS  HYPOGLOSSUS.  f 

The  Hypoglossal  Nerve,  (jYervus  Hypoglossus,  Lingualis,)  having 
arisen  from  the  medulla  oblongata,  and  escaped  from  the  cranium 
through  the  anterior  condyloid  foramen,  adheres  closely  for  an  inch 
to  the  pneumogastric  nerve.  It  descends  between  the  external 
carotid  artery  and  the  internal  jugular  vein,  the  latter  being  behind 
the  other;  and  then  winds  over  the  carotid,  externally,  just  below 
the  origin  of  the  occipital  artery.  It  is  there  covered  by  the  posterior 
belly  of  the  digastricus  and  by  the  stylo-hyoideus.  It  then  passes 
forwards  beneath  the  external  jugular  vein,  and  lower  down  some- 
what than  the  tendon  of  the  digastric  muscle,  and,  finally,  ascends 
to  the  tongue,  being  covered  or  concealed  by  the  mylo-hyoideus 
muscle.  The  nerve  in  this  course,  from  the  external  carotid  to  the 
tongue,  forms  a remarkable  curve,  the  convexity  of  which  is  down- 
wards. 

The  Hypoglossal,  while  adhering  to  the  pneumo-gastric,  commonly 
leaves  a few  filaments  with  it.  As  it  crosses  the  external  carotid,  it 
detaches  a large  branch,  the  Ramus  Descendens  Noni,  which  goes 

* J.  F.  Meckel,  de  Nervis  Faciei,  Mem.  de  l’Acad.  des  S.  de  Berlin,  1751,Oaldani, 
Tab.  247. 

t Anat.  Atlas,  Fig.  621. 


43 


502 


NERVOUS  SYSTEM. 


down  the  neck,  along  the  sheath  of  the  carotid  artery  and  the  internal 
jugular  vein,  in  front  of  the  latter. 

The  ramus  descendens  has  been  beautifully  figured  by  Scarpa,  in 
his  Plates  of  the  Nerves.  According  to  him,  when  it  has  got  about 
half  way  down  the  neck,  but  still  resting  on  the  sheath  of  the  vessels, 
it  detaches,  in  front,  two  filaments,  which,  after  the  course  of  an  inch 
forwards,  unite,  and  then  separate  again  to  be  distributed  to  the 
upper  ends  of  the  omo-hyoid  and  sterno-hyoid  muscles.  The  de- 
scendens noni  then  forms,  an  inch  lower  down,  a small  gangliform 
plexus,  resting  upon  the  sheath  of  the  great  vessels  of  the  neck, 
under  the  omo-hyoid  muscle.  This  plexus  is  joined  by  two  fasci- 
culi, which  descend  from  the  first  and  second  cervical  nerves;  and 
from  it  proceed  downwards,  and  backwards,  two  filaments,  which 
join  the  phrenic  nerve ; also,  one  to  the  lower  part  of  the  omo-hyoid 
muscle  ; and  three  or  more,  which  are  divided  and  distributed  upon 
the  sterno-hyoid  and  thyroid  muscles,  and  upon  the  muscles  of  the 
larynx.  Meckel  states,  that  some  of  these  ramifications  on  the  left 
side  principally,  penetrate  to  the  thorax,  and  reach  the  pericardium. 

The  hypoglossal  nerve,  having  sent  off  the  ramus  descendens, 
reaches  the  external  face  of  the  hyo-glossus  muscle,  and  is  there 
concealed  by  the  mylo-hyoideus,  where  it  gives  filaments  to  the 
muscles  of  the  larynx,  to  the  hyo-glossus,  genio-hyoideus,  and  ge- 
nio-hyo-glossus.  These  filaments  anastomose  frequently  with  each 
other,  and  in  two  or  three  places  at  the  anterior  part  of  the  tongue 
with  the  lingual  branch  of  the  nervus  trigeminus.  After  these 
branches  are  given  off,  the  trunk  of  the  hypo-glossal  nerve  pene- 
trates into  the  substance  of  the  genio-hyo-glossus  muscle,  and  ex- 
tends itself  near  its  fellow,  and  not  far  from  the  middle  line  of  the 
tongue  to  the  point  of  the  latter.  It  first  distributes  filaments  near 
the  posterior  part  of  the  tongue,  and  then,  successively,  as  far  as  its 
anterior  extremity.  They  cannot  be  traced  to  the  papillae,  but  are 
lost  upon  the  muscular  structure. 

It  is  a general  opinion  among  anatomists  that  the  hypo-glossal 
nerve  is  only  intended  to  excite  the  muscular  movements  of  the 
ongue.  The  opinion  is  founded  upon  the  circumstance  of  its  fila- 
ments not  reaching  the  papillae,  whereas  those  of  the  lingual  branch 
of  the  trigeminus  do,  Colombo  narrates  a case,  in  which  there  was 
a congenital  privation  of  taste,  where  the  lingual  branch  of  the  tri- 
geminus was  distributed  upon  the  occiput  instead  of  upon  the 


NERVUS  ACCESSORIUS. 


503 


tongue,  which  goes  far  to  prove  the  difference  of  function  in  the  two 
nerves. 

SECT.  IX. — NERVUS  ACCESSORIUS.* 

The  Accessory  Nerve,  ( JYervus  Accessorius  Willisii ,)  having 
arisen,  as  described  from  the  cervical  medulla  and  the  medulla  ob- 
longata, is  directed  outwards  to  the  posterior  foramen  lacerum,  in 
company  with  the  pneumogastric  or  par  vagum.  Sometimes  it  is 
separated  from  it  in  its  passage  through  the  base  of  the  cranium,  by 
a thin  partition  of  dura  mater;  on  other  occasions  merely  by  a fold 
of  the  tunica  arachnoidea:  but  at  the  inferior  part  of  this  foramen  it 
adheres  closely  to  the  par  vagum,  so  that  the  two  look  like  but  one 
nerve. 

Near  its  exit  it  is  divided  into  two  fasciculi.  The  internal  gives 
off  one  or  two  filaments,  which  joining  a branch  of  the  par  vagum, 
forms  the  superior  pharyngeal  nerve  ; the  internal  branch  then  de- 
scends, and  being  divided  into  several  branches,  they,  successively, 
join  the  upper  part  of  the  par  vagum.  The  external  fasciculus  de- 
scends for  two  inches  behind  the  internal  jugular  vein,  being  placed 
first  of  all  between  it  and  the  occipital  artery,  but  subsequently  be- 
tween the  vein  and  the  sterno-mastoid  muscle.  It  then  pierces  this 
muscle  about  one  third  of  the  length  of  the  latter  from  its  superior 
extremity,  and  leaves  filaments  in  it  which  anastomose  with  some 
from  the  third  cervical  nerve.  In  continuing  its  descent,  it  is  re- 
enforced and  augmented  considerably  in  volume,  by  branches  from 
the  second  and  the  third  cervical.  Having  reached  the  an- 
terior margin  of  the  trapezius  muscle,  it  then  distributes  itself  to  the 
latter,  by  internal  and  by  external  branches. 

The  spinal  accessory  and  the  par  vagum  are  compared  by  Goerresf 
to  the  anterior  and  posterior  roots  of  a spinal  nerve.  The  enlarge- 
ment of  the  vagum  in  the  foramen  lacerum  being  considered  gangli- 
onic, is  in  favour  of  the  analogy.  . 

SECT.  X. — NERVUS  GLOSSO-PH ARYNGEUS. £ 

The  Glosso-Pharyngeal  Nerve  ( JYervus  Glosso-Pharyngeus ,) 
though  commonly  considered  as  distinct  from  the  pneumogastric, 

* Anat.  Atlas,  Fig.  623.  t Muller,  p.  658.  t Anat.  Atlas,  Fig.  623; 


504 


NERVOUS  SYSTEM. 


has  so  many  connexions  with  it,  both  at  its  root,  in  its  course 
through  the  posterior  foramen  lacerum,  and  in  its  distribution  that  it 
seems  like  a part  or  branch  of  the  same.  At  the  inferior  base  of  the 
cranium  in  front  of  the  pneumogastric,  it  forms  according  to  some 
anatomists,*  a ganglion  of  five  or  six  lines  in  length,  (Ganglion  Pe- 
trosum,)  the  existence  of  which  was  denied  by  Bichat.  From  this 
ganglion  proceeds  a filament, f which  penetrates  into  the  tympanum 
and  divides  into  two  branches;  one  of  them  ascends  along  the  pro- 
montory, having  detached  a filament  to  the  membrane  of  the  foramen 
rotundum:  it  then  penetrates  the  petrous  bone;  and  anastomoses  or 
joins  with  the  superficial  petrous  nerve.  The  other  branch  passes 
below  the  bony  Eustachian  Tube,  and,  gaining  the  carotid  canal, 
anastomoses  there  with  the  Sympathetic  Nerve..  This  is  part  of  the 
anastomosis  of  Jacobson,  and  is  also  described  in  the  account  of  the 
Vidian  Nerve. ij:  The  ganglion  also  gives  off  other  filaments,  which 

join  the  pneumogastric  nerve,  the  accessory  and  the  sympathetic. 

On  issuing  from  the  posterior  foramen  lacerum,  the  glosso-phauyn- 
geal  is  separated  from  the  pneumogastric  by  the  internal  jugular 
vein.  It  is  then  directed  downwards  and  forwards  between  the 
internal  carotid  and  the  stylo-pharyngeus  muscle,  afterwards  be- 
tween the  latter  and  the  stylo-glossus ; it  follows  the  direction  of  the 
latter  to  the  side  of  the  root  of  the  tongue. 

In  this  course  it  sends  off  many  filaments.  Shortly  after  leaving 
the  cranium,  it  detaches  one  backwards  to  the  digastric  branch  of 
the  facial,  and  another  to  the  pneumogastric.  It  then  sends  off  two 
filaments,  which  descend  along  the  internal  and  common  carotid, 
and  are  divided  into  several  branches;  some  of  which  anastomose 
with  the  pharyngeal  branch  of  the  pneumogastric;  others  descend 
on  the  common  carotid  with  filaments  from  the  pharyngeal  branch, 
and  being  joined  by  two  or  three  small  twigs  from  the  superior  cer- 
vical ganglion;  they  reach  the  lower  part  of  the  neck,  and  concur  in 
the  forming  of  the  superficial  cardiac  nerve.  Farther  down,  after  the 
origin  of  these  branches,  the  glosso-pharyngeal  detaches  two  or  three 
filaments  to  the  stylo-pharyngeus  muscle,  as  well  as  some  to  the 
upper  and  middle  constrictors  of  the  pharynx,  to  the  pharyngeal 

* Andersach  and  Huber.  This  ganglion  is  considered  by  some  as  commencing 
before  the  nerve  penetrates  the  foramen  lacerum  ; others,  as  Muller,  say  that  there  is 
at  this  point  a ganglion  besides  the  lower  one,  but  that  all  the  fibres  do  not  concur  to 
form  it. 

t Rosenmuller,  Jacobson,  Lobstein.  t See  Nerves  of  Organ  of  Hearing,  p.  483. 


NERVUS  PNEUMOGASTRICUS. 


505 


plexus  of  the  sympathetic  and  pneumogastric,  and  to  the  posterior 
lateral  and  superficial  part  of  the  tongue. 

The  glosso-pharyngeal  nerve  having  got  between  the  stylo  and 
hyo-glossus  muscle,  is  placed  intermediately  to  the  lingual  branch  of 
the  fifth  pair  and  the  hypo-glossal  nerve.  Some  of  its  branches  then 
go  to  the  integuments  of  the  base  of  the  tongue,  to  its  mucous  glands, 
large  papillae,  and  may  be  traced  to  the  mucous  membrane  of  the 
soft  palate,  to  the  amygdalae,  and  to  the  covering  membrane  of  the 
epiglottis.  Others  go  into  the  muscles  of  the  tongue,  and  others 
may  be  traced  along  the  external  margin  of  the  tongue,  beneath  its 
mucous  membrane  for  some  distance.  Scarpa  has  delineated  a re- 
markable plexus,  which  he  denominates  Circulus  Tonsillaris  Ander- 
schii  or  Anastomosis  Plexuosa,  formed  by  these  several  filaments 
and  by  branches  of  the  lingual,  on  the  side  of  the  root  of  the  tongue, 
at  the  base  of  the  tonsil  gland. 

SECT.  XI. — NERVUS  PNEUMOGASTRICUS.* 

The  Pneumogastric  Nerve  ( JVervus  Pneumogastricus , Vagus , Par 
Octavum , Decimum  of  Andersach ,)  at  its  exit  from  the  cranium 
through  the  posterior  foramen  lacerum,  in  front  of  the  internal  jugu- 
lar vein,  is  closely  united  to  the  hypo-glossal,  glosso-pharyngeal, 
and  accessory  nerves,  by  compact  cellular  substance.  It  is  first 
placed  in  front  of  the  hypo-glossal  nerve,  but,  in  a short  space,  gets 
behind  it,  and  is  also  separated  from  the  glosso-pharyngeal  by  the 
internal  jugular  vein.  Opposite  the  transverse  process  of  the  atlas, 
it  leaves  the  hypo-glossal  nerve,  and  assumes  a position  between  the 
internal  carotid  and  the  internal  jugular,  on  the  vertebral  side  of  these 
vessels,  and  is  enveloped  in  their  sheath  of  dense  cellular  substance. 
It  maintains  this  relative  position  along  the  common  carotid  to  the 
root  of  the  neck. 

At  the  latter  place,  the  pneumogastric  of  the  right  side  goes  in 
front  of  the  subclavian  artery,  near  its  root,  but  on  the  left  side  it 
crosses  the  root  of  the  left  subclavian  artery,  and  the  arch  of  the 
aorta  to  the  left  of  the  origin  of  the  left  carotid.  In  getting  fairly 
into  the  cavity  of  the  thorax,  it  is  directed  backwards  and  down- 
wards from  these  points  towards  the  posterior  face  of  the  bronchus, 
between  it  and  the  pleura.  It  then  abandons  the  bronchus,  and 
applies  itself  to  the  oesophagus,  and  follows  it  through  the  diaphragm 


Anat.  Atlas,  Figs.  622,  623. 


506 


NERVOUS  SYSTEM. 


to  the  stomach.  The  nerve  of  the  left  side,  in  its  course  along  the 
(Esophagus,  is  on  the  front  surface  of  the  latter,  and  the  nerve  of  the 
right  side,  on  its  posterior  surface. 

The  pneumogastric  anastomoses  with  the  accessory  while  passing 
through  the  foramen  lacerum  posterius.  Somewhat  lower  down,  it 
also  anastomoses  with  the  glosso-pharyngeal  and  with  the  superior 
cervical  ganglion  of  the  sympathetic.  The  branches  which  it  after- 
wards sends  off,  go  to  the  neck,  to  the  viscera  of  the  thorax,  and  to 
those  of  the  abdomen,  after  the  following  manner: — 

A.  Cervical  Branches.  The  Superior  Pharyngeal  Nerve  ( Ramus 
Pharyngeus)  arises  just  below  the  preceding  anastomosis.  It  is  di- 
rected downwards  on  the  internal  face  of  the  internal  carotid,  and 
having  sent  an  anastomotic  filament  to  the  glosso-pharyngeal  nerve; 
it  forms  on  the  middle  constrictor  of  the  pharynx,  the  pharyngeal 
plexus  which  is  re-enforced  by  filaments  from  the  superior  cervical 
ganglion  of  the  sympathetic,  from  the  glosso-pharyngeal,  and  from 
the  superior  laryngeal  nerve.  The  filaments  departing  from  this 
plexus,  are  spent  principally  upon  the  middle  constrictor,  but  a few 
of  them  also  go  to  the  superior  constrictor ; and  others,  descending 
along  the  primitive  carotid,  anastomose  with  ramifications  from  the 
glosso-pharyngeal,  and  from  the  superficial  cardiac  nerve. 

A filament,  called  the  Inferior  Pharyngeal,  sometimes  proceeds 
from  the  pneumogastric  a little  below  the  other,  and  also  is  spent 
upon  the  pharynx. 

The  pneumogastric,  at  the  place  where  it  detaches  these  pharyn- 
geal branches,  or  a little  above  them,  becomes  softened  in  its  tex- 
ture, enlarges  somewhat,  and  has  the  fasciculi  which  compose  it 
moderately  separated  by  a sort  of  red  gelatinous  substance  inter- 
posed between  them.  This  portion  is  its  gangliform,  plexus , and 
into  it  is  joined  one  or  more  branches  from  the  accessory  nerve. 

The  Superior  Laryngeal  Nerve  ( JYervus  Laryngeus  Superior ) 
arises  from  the  gangliform  plexus.  It  descends  between  the  inter- 
nal carotid  and  the  superior  cervical  ganglion,  anastomosing  on  the 
way  with  the  latter,  with  the  pharyngeal  plexus,  and  the  hypoglossal 
nerve  ; it  then  divides  into  an  external  and  an  internal  laryngeal 
branch.  The  former  sends  its  filaments  to  the  muscles  situated  on 
the  fore  part  of  the  thyroid  cartilage  ; to  the  thyroid  gland  ; and  some 
of  them  penetrate  through  the  middle  crico-thyroid  ligament  to  the 
lining  membrane  of  the  larynx.  The  internal  laryngeal  branch  is 


PNEUMOGASTRIC  NERVE. 


507 


placed  above  the  other ; it  is  directed  towards  the  middle  thyreo- 
hyoid  ligament,  which  it  penetrates  and  then  begins  to  ramify.  Some 
of  the  branches  go  to  the  epiglottis  cartilage,  its  covering  membrane, 
and  the  adjacent  portion  of  the  lining  membrane  of  the  pharynx. 
Other  branches  are  distributed  to  the  small  muscles  which  move  the 
arytenoid  cartilages,  and  to  the  lining  membrane  of  the  larynx.  The 
filaments  which  go  to  the  epiglottis  have  an  arrangement  indicated 
by  Bichat ; that  of  going  into  the  foramina  which  perforate  it,  but 
they  cannot  be  traced  farther. 

The  pneumogastric  afterwards  does  not  send  off  any  regular 
branches  till  it  reaches  the  lower  part  of  the  neck.  It  then  detaches 
two  or  three  filaments,  ( rami  cardiaci ,)  which,  on  the  right  side, 
have  their  roots  about  an  inch  above  the  subclavian  artery,  and  on 
the  left  side,  an  inch  lower  down.  On  the  right  side,  they  descend 
along  the  subclavian  and  the  arteria  innominata,  and  on  the  left  along 
the  left  carotid;  they  reach  the  arch  of  the  aorta,  and  in  their  course,  as 
well  as  there,  anastomose  very  freely  with  the  superficial  cardiac 
nerve.  The  rami  cardiaci  are  frequently  more  abundant  on  the  right 
side  than  on  the  left. 

The  Inferior  Laryngeal  Nerve  (JYervus  Laryngeus  Inferior , Recur - 
rens)  is  a considerable  branch  of  the  pneumogastric,  which  comes 
off  next  to  the  cardiac  branches.  On  the  right  side  it  arises  imme- 
diately after  the  trunk  has  passed  between  the  subclavian  artery  and 
the  subclavian  vein.  It  then  winds  around  the  subclavian  artery 
so  as  to  retain  the  latter  in  its  loop  ; having  thus  got  behind  the 
artery,  it  then  ascends  towards  the  larynx,  on  the  side  of  the  trachea, 
covered  by  the  common  carotid,  and  by  the  inferior  thyroid  artery. 

In  this  course  the  inferior  laryngeal  nerve  detaches  the  following 
branches:  1.  From  the  convexity  of  its  loop  it  sends  filaments  to 

the  assistance  of  the  cardiac  branches  just  spoken  of,  arising  from 
the  pneumogastric,  and  to  those  coming  from  the  inferior  cervical 
ganglion  of  the  sympathetic.  2.  It  detaches  the  pulmonary  branches, 
the  origin  of  which  is  complicated  with  the  plexus  of  nerves  existing 
about  their  roots ; these  descend  in  front  of  the  trachea,  reach  the 
pulmonary  artery,  and  follow  its  ramifications  into  the  lungs ; some 
of  the  filaments,  however,  go  to  the  cardiac  plexus.  3.  The  inferior 
laryngeal  then  sends  many  filaments  to  the  oesophagus;  4.  Branches 
which  go  to  the  inferior  part  of  the  thyroid  gland  ; 5.  Filaments  to 
the  trachea,  some  of  which  penetrate  the  membrane  on  its  posterior 


508 


NERVOUS  SYSTEM. 


part,  others  go  between  the  cartilages ; they  are  then  distributed  to 
the  lining  membrane  and  to  the  mucous  glands  of  the  part.  6.  The 
inferior  laryngeal  nerve  is  then  distributed  in  branches  to  the  inferior 
constrictor  of  the  pharynx  and  its  lining  membrane,  but  the  most  of 
its  terminating  filaments  penetrate  to  the  larynx,  between  the  thyroid 
and  the  cricoid  cartilage,  and  are  lost  upon  the  lining  membrane  of 
the  larynx,  and  upon  the  small  muscles  which  move  the  arytenoid 
cartilages.  These  terminating  filaments  anastomose  with  such  as 
come  from  the  superior  laryngeal  nerve. 

It  is  stated  by  some  anatomists  that  the  distribution  of  the 
inferior  laryngeal  nerve  to  the  larynx,  is  confined  to  the  thyreo- 
arytenoid,  and  posterior  and  lateral  crico-arytenoid  muscles.  Mr. 
G.  Rainy  states,  in  the  London  Medical  Gazette,  that  he  has  re- 
peatedly traced  its  filaments,  also,  to  the  transverse  and  the  oblique 
arytenoid.* 

The  recurrent  of  the  left  side  forms  a much  larger  loop  than  the 
other,  and  arises  lower  down,  inasmuch  as  it  has  to  wind  around 
the  arch  of  the  aorta,  at  the  origin  of  the  left  subclavian  artery : with 
some  inconsiderable  exceptions,  its  course  and  distribution  after- 
wards are  precisely  the  same  with  those  of  the  nerve  of  the  right 
side. 

B.  The  Thoracic  Branches  of  the  pneumogastric  are  as  follow : 
The  inferior  tracheal  nerves  come  from  it  just  below  the  recurrent : 
they  are  five  or  six  in  number  ; some  of  them  go  in  front  of  the  trachea 
and  bronchus,  and  others  behind  them.  They  are  complicated  by 
anastomoses  with  the  branches  of  the  recurrent  nerve,  and  with  those 
of  the  inferior  cervical  ganglion,  and  form  a small  intertexture  deno- 
minated the  Anterior  pulmonary  plexus,  which  lies  upon  the  front  of 
the  root  of  the  lung,  and  has  its  filaments  following  the  branches  of 
the  pulmonary  artery  through  the  lung.  The  posterior  filaments 
supply  the  structure  of  the  bronchus  by  penetrating  it,  and  some  of 
them  go  to  join  the  posterior  pulmonary  plexus. 

As  the  pneumogastric  gets  behind  the  trachea  and  the  bronchus, 
it  is  sensibly  enlarged  and  somew'hat  flattened,  the  cohesion  of  its 
fasciculi  being  somewhat  looser.  Several  filaments  depart  there 
from  it,  which  form  an  intertexture  with  each  other ; some  of  them 
pass  inwards,  to  be  distributed  on  the  bronchus,  trachea,  and  ceso- 


* Am.  Med.  Journ.,  vol.  iv.,  p.  198. 


PNEUMOGASTRIC  NERVE. 


509 


phagus.  Others,  which  are  given  off  as  the  nerve  lies  upon  the 
posterior  face  of  the  root  of  the  lung,  amounting  to  six  or  seven  in 
number,  but  being  of  various  sizes,  run  transversely  outwards,  and 
form  an  intertexture  with  one  another.  The  latter  are  joined  by 
filaments  from  the  inferior  cervical  and  the  first  dorsal  ganglion  of 
the  sympathetic,  and  thus  constitute  the  Poswrior  pulmonary  plexus. 
The  fdaments  from  this  plexus  follow  the  distribution  of  the  bronchus, 
and,  according  to  Bichat,  are  all  destined  to  the  mucous  membrane 
and  the  mucous  glands  of  the  lung;  as  they  may  be  traced  piercing 
successively  the  ramifications  of  the  bronchus,  in  order  to  reach  its 
lining  membrane. 

On  the  right  side,  the  par  vagum,  while  furnishing  the  pulmonary 
plexus,  and  for  some  distance  lower  down,  is  divided  into  from  four 
to  six  considerable  fasciculi,  which  form  with  each  other  a plexus  or 
series  of  anastomoses,  having  very  large  meshes,  and  from  which 
proceed  many  fdaments  to  the  oesophagus.  Afterwards  the  fasciculi 
are  assembled  into  a single  cord,  which  proceeds  on  the  posterior 
face  of  the  oesophagus,  along  with  it  into  the  abdomen. 

On  the  left  side,  the  par  vagum,  after  forming  the  posterior  pul- 
monary plexus,  is  split  into  two  or  three  fasciculi ; which  likewise 
furnish  branches  to  the  oesophagus,  and  unite  to  form  a single  cord, 
which  proceeds  on  the  front  surface  of  the  oesophagus,  along  with  it 
into  the  abdomen. 

The  two  nerves,  while  descending  in  this  way,  send  frequent  an- 
astomotic filaments  to  each  other,  and  to  the  oesophagus. 

C.  In  the  Abdomen  the  par  vagum  is  distributed  as  follows:  Fila- 
ments are  sent  from  each  nerve,  and  which  form  a plexus  around 
the  cardiac  orifice  of  the  stomach.  The  right  nerve  is  then  divided 
into  many  branches ; some  are  distributed  on  the  posterior  face  of 
the  stomach,  others  go  along  the  lesser  curvature  of  this  viscus,  and 
reach  thereby  the  pylorus,  where  they  anastomose  with  filaments 
from  the  left  nerve,  and  from  the  gastric  plexus  of  the  sympathetic  ; 
others  go  behind  the  stomach  to  join  the  solar  plexus,  and  are 
blended  with  the  latter  in  its  distribution  to  the  liver,  vena  portarum, 
duodenum,  and  pancreas.  The  left  par  vagum,  being  placed  in 
front  of  the  cardia,  is  resolved  into  several  radiating  filaments  or 
fasciculi,  some  of  which  supply  the  anterior  face  of  the  stomach, 
others  go  along  its  lesser  curvature  to  the  pylorus,  to  anastomose 
with  the  right  nerve  and  the  gastric  branches  of  the  sympathetic, 
Vol.  II.— 44 


510 


NEHVOUS  SYSTEM. 


and  are  finally  blended,  after  the  same  manner  as  the  preceding, 
with  the  solar  plexus. 


CHAPTER  II. 

Of  the  Sympathetic  Nerve.* 

The  Sympathetic  Nervef  ( JVervus  Symphatheticus  Magnus , Inter- 
cost  alls  Maximus , Gangliosus ,)  differs,  in  a great  number  of  respects, 
from  every  other  nerve  of  the  body ; and  if  we  were  actuated  only 
by  its  pecularities,  with  Bichat,  Meckel,  and  others,  we  might,  with 
great  propriety,  set  it  apart  as  something  having  a claim  to  an  insu- 
lated description  and  location.  The  dissection  of  it,  however,  is  so 
much  blended  with  that  of  the  par  vagum,  that  the  descriptions  of 
the  two  go  best  hand  in  hand,  and  are,  therefore,  most  conveniently 
studied  together. 

This  nerve  consists  in  a series  or  chain  of  ganglions,  extending 
from  the  base  of  the  cranium  to  the  lower  end  of  the  sacrum.  They 
are  placed  on  the  lateral  part  of  the  bodies  of  the  vertebrae,  are  united 
to  each  other  by  intermediate  nervous  cords,  and  send  off  continually 
filaments  to  the  adjacent  organs.  With  the  exception  of  the  neck, 
there  is  a ganglion  for  each  intervertebral  space  both  of  the  true  ver- 
tebra and  sacrum.  Besides  these  ganglions,  there  are  others  which 
are  situated  around  the  trunks  of  some  of  the  large  vessels  of  the 
abdomen  4 

The  superior  extremity  of  the  sympathetic  nerve,  opposite  to  the 
transverse  process  of  the  second  cervical  vertebra,  and  behind  the 
internal  carotid  artery,  forms  a ganglion,  which,  for  the  purpose  of 
description,  may  be  considered  as  the  first  of  the  series.  This  gang- 
lion is  the  Superior  Cervical. 

The  nervus  motor  externus  oculi,  in  passing  through  the  cavernous 
sinus,  and  the  Vidian  nerve,  in  passing  by  the  point  of  the  petrous 

* Anton.  Scarpa.  Tabul.  Neurolog. 

t Anat.  Atlas,  Fig.  624. 

t In  the  ganglia  of  the  sympathetic,  it  is  doubtful,  whether  the  separate  nervous 
filaments  really  unite,  or  keep  distinct. 


THE  SYMPATHETIC  NERVE. 


511 


bone,  both  send  a filament  downwards  through  the  carotid  canal ; 
which  two  filaments  unite  to  form  a single  chord,  that  runs  into  the 
superior  extremity  of  this  ganglion.  The  filament  from  the  Vidian 
nerve  is,  as  mentioned,  the  deep  petrous  nerve.  The  common  view 
taken  by  anatomists  of  this  nervous  connexion  is,  that  it  is  the  be- 
ginning of  the  sympathetic,  though,  by  Bichat,  it  is  described  as  the 
termination,  or  one  of  its  extremities.  The  distinction,  though  im- 
portant physiologically,  is  less  so  when  the  object  is  simply  to  de- 
scribe the  course  and  anatomical  relations  of  this  nerve,  as  they  may 
be  equally  understood  by  either  mode  of  description. 

The  branch  from  the  deep  Petrous  most  frequently  forms,  on  the 
external  face  of  the  internal  carotid,  in  the  cavernous  sinus,  or  more 
generally  in  the  carotid  canal,  a ganglion,  ( Ganglion  Cavsrnosum , 
Caroticum,)  discovered  by  Laumonier.  Some  anatomists  consider 
this  ganglion  to  arise  by  one  or  more  filaments,  from  the  motor  ex- 
ternus.  This  ganglion,  to  say  the  most  of  it,  is  an  elongated  flattened 
enlargement  of  the  trunk  of  the  deep  petrous,  in  many  subjects  if 
not  in  most,  scarcely  meriting  the  name  of  ganglion.*  From  the 
ganglion  cavernosurn,  it  has,  of  late,  been  ascertained  that  filaments 
may  be  traced  to  the  ganglion  of  Gasser,  ( Plexus  Gang/iformis,)  of 
the  trigeminus,  to  the  pituitary  gland,  to  the  infundibulum;  and, 
moreover,  a fasciculus  which,  according  to  H.  Cloquet,  forms  a 
plexus  around  the  ophthalmic  artery,  and  may  be  traced  along  all 
its  branches,  even  the  central  artery  of  the  retina.  This  plexus  an- 
astomoses with  the  lenticular  ganglion,  and  consequently  establishes 
a direct  nervous  communication  between  the  sympathetic,  and  the 
first  branch  of  the  fifth  pair.  The  knowledge  of  this  connexion  has 
caused  anatomists  to  locate  the  lenticular  ganglion  and  the  ciliary 
nerves  in  the  ganglionic  system  of  the  sympathetic,  as  forming  a 
part  of  the  latter. 

From  the  ganglion  of  Laumonier  may  also  be  traced  a filament, 
which,  attending  the  carotid  in  its  ascent  by  the  sella  turcica,  follows 
also  the  anterior  artery  of  the  brain,  or  arteria  callosa ; and  having 
reached  the  anterior  communicating  artery,  it  runs  into  a ganglion 
on  the  middle  of  this  artery,  the  ganglion  being  common  to  it  and 
the  nerve  of  the  opposite  side.  This  is  the  Ganglion  of  Ribes,  and 

* M.  Lobstein,  in  his  Essay  on  the  Sympathetic,  (Palis,  1823,)  a work  of  much 
merit,  has  also  attributed  this  ganglion  to  the  deep  petrous  nerve,  in  which  I thought 
for  many  years  he  was  mistaken,  though  renewed  observations  have  now  convinced 
me  of  his  correctness. 


512 


NERVOUS  SYSTEM. 


establishes  for  the  extreme  upper  end  of  the  two  sympathetic?  an 
anastomosis,  or  connexion  on  the  same  principle  that  the  two  lower 
ends  communicate  by  anastomosis  in  front  of  the  os  coccvgis. 

The  sympathetic,  in  descending  the  neck,  is  placed  behind  the 
carotid  artery  and  internal  jugular  vein.  It  is  commonly  said  to  be 
enclosed  in  the  sheath  of  these  great  vessels,  but  the  statement  is 
loose  and  inaccurate,  as  it  is  fastened  to  the  front  surface  of  the 
longus  colli  muscle  by  cellular  substance  distinct  from  the  sheath, 
as  may  be  manifested  by  pushing  a knife  handle  between  them  and 
raising  up  the  sheath.  The  chord  which  comes  down  from  the  ca- 
rotid canal  is  close  to  the  pneumogastric  and  hypoglossal  nerves. 
Having  formed  the  first  cervical  ganglion,  it  descends  as  mentioned  ; 
and,  opposite  to  the  space  between  the  fifth  and  sixth  cervical  ver- 
tebras, it  is  again  enlarged  into  the  Middle  Cervical  Ganglion,  which 
is  much  smaller  and  more  irregular  than  the  first.  The  sympathetic 
is  then  traced  with  some  difficulty,  in  consequence  of  the  numerous 
branches  coming  from  it;  but,  with  attention,  a trunk  may  be  found 
as  the  continuation  of  it.  This  trunk  passes  to  the  interval  between 
the  head  of  the  first  rib  and  the  transverse  process  of  the  last  cervical 
vertebra,  and  there  enlarges  into  another  ganglion,  called  Inferior 
Cervical  or  First  Dorsal, 

To  understand  well  the  connexions  of  the  sympathetic  in  the  neck, 
each  of  the  cervical  ganglions  must  be  studied  particularly. 

1st.  The  Superior  Cervical  Ganglion  varies  considerably  in  its 
extent;  commencing  very  generally  opposite  to  the  second  cervical 
vertebra,  it  is  somewhat  elongated  to  the  lower  part  of  the  third  and 
even  of  the  fourth.  In  cases  of  unusual  elongation,  it  is  smaller  than 
in  others. 

It  sends  off,  from  its  external  margin,  several  filaments,  about  four, 
which  cross  the  anterior  face  of  the  rectus  anticus  major  muscle,  and 
terminate  by  anastomosing  with  the  anterior  fasciculus  of  the  occi- 
pital nerve  and  of  the  first  three  cervical;  when  the  ganglion  is  short, 
the  two  lower  filaments  come  from  the  sympathetic  below  it,  instead 
of  from  the  ganglion. 

Several  filaments  also  proceed  from  this  ganglion  to  the  contigu- 
ous muscles  on  the  vertebral  column,  to  the  pharynx,  to  the  larynx, 
and  to  the  thyroid  gland. 

This  ganglion  also  sends  off  what  are  called  its  Anterior  branches, 
which  are  peculiar  for  their  reddish  colour  and  for  their  softness  ; 


THE  SYMPATHETIC  NERVE. 


513 


the  latter  quality  has  obtained  for  them  the  name  of  Nervi  Molles. 
They  may  be  referred,  by  their  position,  to  three  orders.  The  su- 
perior ascend  to  anastomose  with  the  pneumogastric,  hypoglossal, 
and  facial  nerves,  near  their  exit  from  the  cranium.  The  middle 
are  two  or  three  in  number,  but  immediately  divide  into  many  fila- 
ments, forming  the  carotid  plexus  by  assistance  from  the  pneumc- 
gastric,  glosso  pharyngeal,  and  facial  nerves.  Some  of  the  branches 
of  this  plexus  descend  behind  the  primitive  carotid  at  the  place  of 
its  bifurcation,  and  accompany  it  to  its  origin,  continually  interlacing 
with  each  other.  Others  surround,  after  the  same  manner,  the  ex- 
ternal carotid,  and  subdivide  into  a plexus  for  each  of  its  branches, 
so  that  very  fine  filaments  may  be  traced  along  the  superior  thy- 
roidal, the  lingual,  facial,  occipital,  and  temporal  arteries.  These 
nerves  are,  for  the  most  part,  difficult  to  trace,  from  their  extreme 
tenuity.  The  primitive  branches,  from  which  these  plexuses  come 
are  sometimes  previously  united  into  a small  ganglion,  which  serves 
as  a common  centre  to  all  these  nervous  radiations.  The  third  order 
of  anterior  branches  amounting  to  from  four  to  six,  comes  either  from 
the  ganglion  or  from  the  sympathetic  just  below  it.  A chord  formed 
by  their  union,  called  the  Superficial  Cardiac  Nerve,  descends  on  the 
external  side  of  the  primitive  carotid,  anastomosing  with  filaments 
from  the  pneumogastric  and  from  the  descendens  noni.  It  gives 
small  ramifications  to  the  contiguous  parts,  as  to  the  pharynx,  oeso- 
phagus, the  sterno-hyoid  and  thyroid  muscles.  It  terminates  in  the 
lower  part  of  the  neck,  by  detaching  anastomosing  branches  to  the 
branches  of  the  recurrent  nerve  ; some  of  them  also  go  along  the  in- 
ferior thyroid  artery,  to  the  thyroid  gland.  What  remains  of  it  is  lost 
in  the  middle  cardiac  nerve ; for  it  cannot  be  traeed,  in  an  insulated 
and  distinct  manner  to  the  heart ; from  which  cause  its  appellation  is 
objectionable. 

2.  The  Middle  Cervical  Ganglion , placed  intermediately  to  the 
fifth  and  sixth  cervical  vertebrae,  upon  the  longus  colli  muscle,  is 
•there  concealed  by  the  common  carotid,  the  internal  jugular  vein, 
and  the  pneumogastric  nerve.  It  is  sometimes  deficient : according 
to  Meckel,  in  the  proportion  of  once  in  three  times.  In  my  own 
dissections  I have  always  found  it,  though  under  various  circum- 
stances of  size  and  form.  It  is  more  flattened  than  the  preceding 
and  never  so  long.  Sometimes  it  is  double.  Like  the  preceding, 
it  has  a great  many  filaments  attached  to,  or  emanating  from  it. 

The  external  filaments,  amounting  to  about  three  in  number,  pass 

44* 


514 


NERVOUS  SYSTEM. 


from  it  to  the  anterior  fasciculi  of  the  fourth,  fifth  and  sixth  cervical 
nerves,  between  the  origins  of  the  scaleni  muscles.  Some  of  its 
filaments  accompany  the  inferior  thyroid  artery,  and,  along  with  the 
superficial  cardiac,  form  a plexus  around  it,  which  reaches  to  the 
thyroid  gland. 

The  Middle  Cardiac  Nerve  is  formed  by  several  of  the  anterior 
branches,  collecting  into  a single  cord.  The  latter  descends  along 
the  external  side  of  the  primitive  carotid,  crosses  on  the  right  side 
of  the  body,  the  root  of  the  subclavian  artery ; and  then  going  along 
the  posterior  face  of  the  arteria  innominata,  it  gets  between  the 
aorta  and  the  bifurcation  of  the  trachea ; where,  it  is  merged  in  the 
commencement  of  the  cardiac  plexus  of  nerves.  On  the  left  side, 
the  middle  cardiac  nerve  is  formed  by  an  assemblage  of  filaments 
from  the  middle  and  inferior  cervical  ganglions,  which  descend 
along  the  left  subclavian  artery  to  the  aorta,  and  are  joined,  on  the 
front  of  the  latter,  by  the  superficial  cardiac  nerve.  On  both  sides, 
these  cardiac  nerves  form  intricate  anastomoses  with  the  pneumo- 
gastric  nerve  and  its  recurrent  branch. 

3.  The  Inferior  Cervical  Ganglion , situated  as  mentioned,  near 
the  head  of  the  first  rib,  like  the  others,  is  subject  to  variations  in  its 
form  and  size.  Several  filaments  may  be  traced  between  it  and  the 
middle  cervical  ganglion.  One  penetrates  into  the  canal  of  the 
transverse  processes  along  with  the  vertebral  artery,  and  forming  a 
plexus  around  it,  may  be  traced  distributing  branches  to  the  heads 
of  the  contiguous  muscles,  as  high  up  as  the  second  cervical  vertebra. 

The  external  branches  of  the  inferior  cervical  ganglion  are  nu- 
merous and  small.  Some  of  them  anastomose  with  the  anterior 
fasciculi  of  the  two  or  three  inferior  cervical  and  the  first  dorsal 
nerve.  Others  form  a plexus  around  the  subclavian  artery,  and 
follow'  the  latter  in  its  distribution,  to  the  upper  extremity  and  to  the 
shoulder. 

The  anterior  branches  of  this  ganglion  concur,  after  some  anasto- 
moses with  each  other,  to  form  a single  chord,  the  Inferior  Cardiac 
Nerve  ; which  goes,  on  the  right  side,  along  the  arteria  innominata, 
to  be  blended  with  the  cardiac  plexus.  On  the  left  side,  it  is  not  so 
distinct,  but  it  is  blended  with  the  middle  cardiac  nerve,  and  forms 
its  inferior  root. 


THE  SYMPATHETIC  NERVE. 


515 


Of  the  Cardiac  Plexus  of  the  Sympathetic. 

The  Cardiac  Plexus  ( Plexus  Cardiacus ) is  situated  between  the 
arch  of  the  aorta,  and  the  lower  part  of  the  trachea  and  the  bron- 
chia, and  extends  from  the  division  of  the  pulmonary  artery  to  the 
commencement  of  the  arteria  innominata.  It  is  formed,  almost 
wholly,  from  the  branches  sent  by  the  three  cervical  ganglions  of 
the  sympathetic  of  each  side,  and  principally  from  that  of  the  mid- 
dle one,  or  the  middle  cardiac  nerve.  The  filaments  which  come 
from  the  recurrent  nerve  and  the  par  vagum  are  blended  into  the 
cardiac  plexus  in  such  a manner  that  they  cannot  be  traced  sepa- 
rately to  the  heart.  It  is  worthy  of  remark,  that  the  three  cardiac 
nerves  of  the  right  side  are  more  constantly  found  than  the  same 
number  on  the  left,  in  consequence  of  the  lower  one  of  the  latter 
soon  merging  itself,  after  its  origin  into  the  middle  cardiac  nerve  of 
that  side. 

The  cardiac  plexus  is  formed  by  the  common  assemblage  of  the 
nerves  from  the  two  sides  of  the  neck,  and  is  therefore  single.  From 
this  plexus  arise  all  the  nerves  which  go  to  the  heart,  so  that  in 
tracing  them  the  distinction  between  right  and  left  is  confounded. 
Scarpa  has  pointed  out,  in  this  circumstance,  an  analogy  between 
them  and  the  nerves  which  supply  the  abdominal  viscera. 

The  cardiac  plexus  is  distinguished  by  the  softness  of  its  texture. 
For  the  purpose  of  description,  its  branches  may  be  divided  into 
Anterior,  Posterior,  and  Inferior. 

The  .Anterior  Branches  are  but  few.  They  are  found  on  the  front 
of  the  arch  of  the  aorta.  One  of  them  crosses  it  on  the  right  side 
of  the  arteria  innominata ; others  cross  it  from  the  foot  of  the  left 
carotid  and  subclavian,  downwards.  In  both  cases,  several  of  the 
terminating  filaments  run  into  the  anterior  coronary  plexus.* 

The  Posterior  Branches  are  more  numerous ; but  run  only  a short 
course,  when  they  are  merged  in  the  anterior  pulmonary  plexus 
formed  by  the  par  vagum. 


* Scarpa* 


516 


NERVOUS  SYSTEM. 


The  Inferior  Branches  are  the  largest  and  the  most  abundant. 
Some  of  them  follow  the  pulmonary  artery  until  its  entrance  into 
the  lungs,  others  are  distributed  upon  the  pulmonary  veins;  but  the 
greater  number  of  them  are  arranged  into  two  plexuses  called 
Coronary,  from  their  observing  the  course  of  the  coronary  arteries. 
The  posterior  coronary  plexus  is  larger  than  the  other.  It  reaches 
the  base  of  the  heart,  along  the  pulmonary  artery,  and  has  its  fila- 
ments distributed  principally  to  the  left  auricle  and  left  ventricle, 
observing  the  course  of  the  left  coronary  artery  and  of  its  branches. 
The  anterior  coronary  plexus  gets  in  front  of  the  heart,  between  the 
aorta  and  the  pulmonary  artery.  It  anastomoses  freely  at  its  supe- 
rior part  with  the  other,  and  is  then  distributed  to  the  right  auricle 
and  ventricle,  along  the  course  of  the  right  coronary  artery  and  of 
its  branches. 


Of  the  Thoracic  Ganglions  of  the  Sympathetic. 

These  ganglions  are  twelve  in  number,  and  are  placed  on  or  near 
the  heads  of  the  ribs,  at  the  commencement  of  each  intercostal 
space,  and  are  only  covered  by  the  pleura.  Their  shape  is  irregular, 
and  they  differ  also  in  size,  being  always  smaller  than  the  cervical 
ganglions.  The  cord  of  the  sympathetic  is  continued,  successively, 
from  one  ganglion  to  another,  so  that  they  form  a complete  chain 
by  their  connexion. 

From  each  ganglion  there  proceeds  one  or  more  external  branches, 
which  go  outwards  to  anastomose  with  the  intercostal  nerve  of  the 
corresponding  part.  Each  ganglion  also  detaches  one  or  more  internal 
branches  or  filaments  to  the  adjacent  parts  lying  on  the  vertebral  co- 
lumn : some  go  to  the  cellular  substance,  others  to  the  longus  colli 
muscle,  others  to  the  aorta,  others  to  the  cardiac  and  to  the  pulmonary 
plexus.  Among  these  internal  branches  there  are  several  which 
concur  to  form  the  Splanchnic  Nerves,  of  which  there  are  two;  the 
Great  and  the  Small. 

The  Great  Splanchnic  JYerve  arises  by  filaments,  from  the  sixth 
to  the  ninth  or  tenth  thoracic  ganglions,  inclusively;  one  or  more 
filaments  coming  from  each  ganglion.  They  are  directed  down- 
wards and  forwards  on  the  sides  of  the  dorsal  vertebrae,  covered  by 
the  pleura,  and  unite,  successively,  into  a trunk  about  the  eleventh 


THE  SYMPATHETIC  NERVE. 


517 


dorsal  vertebra.  This  trunk  penetrates  into  the  cavity  of  the  abdo- 
men, between  the  middle  and  the  internal  part  of  the  lesser  muscle 
of  the  diaphragm,  or  by  the  opening  for  the  aorta. 

Having  got  into  the  abdomen,  the  great  splanchnic  divides  into 
several  fasciculi,  which,  diverging  from  each  other,  are  concealed 
on  the  right  side  by  the  liver,  and  on  the  left  by  the  stomach.  On 
each  side  of  the  aorta  there  is  a large  ganglion  formed  by  an  assem- 
blage of  several  smaller  ones  ; it  is  called  the  Semi-lunar.  In  it  ter- 
minate, for  the  most  part,  these  fasciculi ; some  of  them,  however,  go 
immediately  into  the  solar  plexus,  which  emanates  from  the  semi-lunar 
ganglion. 

The  Small  Splanchnic  JYerve  is  derived,  by  filaments,  from  the 
tenth  and  the  eleventh  thoracic  ganglion.  Having  united,  they 
penetrate  the  crus  of  the  diaphragm,  and,  reaching  the  abdomen,  the 
trunk  is  divided  into  two  branches,  of  which  the  uppermost  ascends 
to  join  the  great  splanchnic  before  its  division,  and  the  lower  de- 
scends to  join  the  renal  plexus. 

Posterior  Renal  JYerves. — Besides  these  two  splanchnic  nerves,  it 
frequently  happens  that  there  are  others  which  come  from  the 
eleventh  and  twelfth  thoracic  ganglions,  and  from  the  communica- 
ting branch  between  the  last  thoracic  and  the  first  lumbar.  They 
unite  into  a trunk  which  goes  to  the  renal  plexus,  and  have  been 
called,  by  Walter,  the  Posterior  Renal  Nerves. 


Of  the  Solar  Plexus. 

The  Semi-lunar  Ganglion,  situated,  as  mentioned,  on  the  side  of 
the  aorta,  is  somewhat  semicircular  or  oval,  and  is  about  an  inch 
long;  its  form,  however,  is  much  diversified  in  different  subjects. 
The  several  ganglions  of  which  it  is  composed,  are  frequently  fused 
into  a single  one.  That  of  the  right  side  is  more  voluminous  than 
the  other,  and  is  placed  between  the  ascending  vena  cava  and  the 
crus  of  the  diaphragm,  somewhat  above  the  right  renal  artery.  That 
of  the  left  is  situated  upon  the  left  crus  of  the  diaphragm,  somewhat 
below  the  splenic  artery.  Between  their  inferior  extremities,  there 
are  generally  two  or  three  smaller  ganglions. 

These  several  ganglions  are  united  by  numerous  filaments, 


518 


NERVOUS  SYSTEM. 


which  send  out  many  ramifications,  and  anastomose  freely  with  each 
other. 

The  preceding  arrangement  may  be  considered  as  the  root  of 
the  Solar  Plexus,  which  extends  from  the  cceliac  artery  to  the  lower 
margin  of  the  emulgents,  and  as  it  is  common  to  the  ganglions  of 
the  two  sides,  it  is  an  inch  and  a half  or  two  inches  wide.  Bichat 
has  very  properly  remarked,  that  this  plexus  seems  to  exist  for  the 
aorta,  as  all  the  divisions  which  it  sends  out  follow  so  exactly  the 
branches  of  this  artery,  that  we  are  forced  to  adopt  the  latter  as  the 
basis  of  the  description.  The  intertexture  and  the  number  of  the 
branches  emanating  from  the  solar  plexus  are  so  complicated,  that  a 
description  of  individual  branches  would  be  almost  endless,  as  well 
as  unintelligible ; anatomists  are,  therefore,  generally  agreed  to  de- 
scribe the  plexus  according  to  the  order  of  the  arteries  which  its  de- 
tachments adhere  to  and  surround. 

1.  The  Diaphragmatic  Plexus  consists  of  a few  filaments  coming 
from  the  superior  part  of  the  solar,  and  following  the  course  of  the 
phrenic  arteries.  Some  of  them  anastomose  with  the  terminating 
filaments  of  the  phrenic  nerve,  in  the  thickness  of  the  diaphragm. 

2.  The  Plexus  which  surrounds  the  Cceliac  Jirtery,  like  it  is  quickly 
disposed  into  three  divisions,  which  follow'  the  branches  of  this 
artery. 

a.  The  Superior  Coronary  Plexus  of  the  stomach,  is  the  small- 
est of  the  three.  It  attends  the  corresponding  artery  along  the  lesser 
curvature  of  the  stomach  to  the  pylorus,  supplying  the  stomach  con- 
tinually with  very  fine  filaments.  In  its  course,  it  anastomoses  with 
the  par  vagum,  and  sends  filaments  to  the  hepatic  plexus. 

h.  The  Hepatic  Plexus  is  the  largest  of  the  three.  It  surrounds 
the  hepatic  artery  and  the  vena  portarum,  and,  in  its  course,  de- 
taches branches  which  go  with  the  right  gastro-epiploic  artery  to  the 
great  curvature  of  the  stomach,  and  constitute  the  inferior  coronary 
plexus.  Branches  are  also  sent  to  the  pancreas  and  to  the  duo- 
denum. The  hepatic  plexus  then  enters  the  transverse  fissure  of 
the  liver,  and  its  branches  may  be  traced  to  the  several  lobes  and  to 
the  gall-bladder. 


THE  SYMPATHETIC  NERVE. 


519 


c.  The  Splenic  Plexus  is  but  small,  and  surrounds  the  splenic  artery. 
The  few  branches  of  vThich  it  is  composed,  anastomose  but  rarely 
with  each  other.  Some  of  them  are  distributed  upon  the  pancreas, 
along  with  the  pancreatic  branches  of  the  splenic  artery ; others  go 
with  the  left  gastro-epiploic  artery  to  the  left  extremity  and  the  greater 
curvature  of  the  stomach  ; the  remainder  penetrate  into  the  substance 
of  the  spleen,  through  its  fissure,  along  with  the  branches  of  the 
splenic  artery. 

3.  The  Superior  Mesenteric  Plexus  is  derived  from  the  solar,  near 
the  superior  mesenteric  artery  ; it  descends  some  short  distance  on 
the  aorta,  before  it  reaches  the  latter.  It  passes  with  the  artery  be- 
tween the  pancreas  and  the  duodenum,  and  is  then  included  be- 
tween the  twojaminse  of  mesentery:  it  is  there  distributed,  by  very 
numerous  filaments,  along  with  the  branches  of  the  artery,  to  the 
whole  of  the  small  intestines,  to  the  ccecum,  and  to  the  ascending 
and  transverse  colon. 

4.  The  Renal  Plexus , one  on  each  side,  is  derived  from  the 
lower  lateral  part  of  the  solar,  and  from  the  Posterior  Renal 
Nerves.  Two  or  three  ganglions,  on  the  root  of  the  renal  artery, 
contribute  to  it,  and  it  is  also  re-enforced  by  an  addition  from  the 
lesser  splanchnic  nerve.  The  branches  which  form  this  plexus  do 
not  anastomose  much,  till  they  get  near  the  kidney  ; they  then 
penetrate  into  its  substance,  through  the  fissure.  Some  filaments 
from  this  plexus  go  to  the  capsula  renalis : others  follow  the 
course  of  the  spermatic  artery,  and  constitute  the  spermatic  plexus 
which  goes  to  the  testicle  in  the  male,  and  to  the  ovarium  in  the 
female. 

5.  The  Inferior  Mesenteric  Plexus  is  a continuation  of  the  solar, 
on  the  anterior  face  of  the  abdominal  aorta.  It  is  much  smaller  than 
the  superior  mesenteric  plexus,  though  it  receives  continually,  in  its 
descent,  filaments  from  the  lumbar  ganglions  of  the  sympathetic.  It 
forms  frequent  anastomoses  around  the  root  of  the  inferior  mesen- 
teric artery,  and  near  the  superior  strait  of  the  pelvis,  is  resolved  into 
two  columns  of  fibres.  One  column  is  distributed  along  with  the 
artery  to  the  rectum,  to  the  sigmoid  flexure  of  the  colon,  and  to  the 
left  section  of  the  latter,  thereby  anastomosing  with  the  colic  branches 
of  the  superior  mesenteric  plexus.  The  other  column  descends  into 


520 


NERVOUS  SYSTEM. 


the  pelvis,  in  front  of  the  sacrum,  and  contributes  to  form  the  hypo- 
gastric plexus,  but  several  of  its  branches  also  follow  the  external 
and  the  internal  iliac  arteries. 

Of  the  Lumbar  Ganglions  of  the  Sympathetic. 

These  ganglions  are  five  in  number,  on  either  side,  and  are  placed 
anteriorly  on  the  sides  of  the  bodies  of  the  lumbar  vertebrae,  near 
the  anterior  margin  of  the  psoas  magnus  muscle.  Their  form  is  ir- 
regular ; they  are  smaller  than  the  cervical  ganglions,  but  larger  than 
the  dorsal. 

The  last  thoracic  ganglion  is  united  to  the  first  lumbar  by  a small 
branch,  which  may  be  considered  as  the  continuation  of  the  sympa- 
thetic. A deficiency  of  this  branch  has,  however,  been  several  times 
observed  by  anatomists ; also  a deficiency  in  the  connecting  nervous 
cord  of  the  ganglions  below.  The  ganglions  themselves  are  incon- 
stant in  their  number,  being  sometimes  less  than  five ; they  vary 
likewise  in  their  situation.  It  is  to  be  understood,  however,  that  in 
a majority  of  subjects,  the  sympathetic  goes  on  uninterruptedly  from 
one  ganglion  to  another,  sometimes  by  one  branch  ; on  other  occa- 
sions, by  two  or  three. 

Each  lumbar  ganglion  sends  outwards  one  or  more  external 
branches,  which  applying  themselves  to  the  body  of  the  contiguous 
vertebra,  reach  the  corresponding  intervertebral  foramen  of  the  loins, 
and  join  with  the  anterior  branch  of  the  corresponding  lumbar  nerve. 
Some  of  these  external  branches  are  spent  upon  the  quadratus  lum- 
borum  muscle. 

Each  lumbar  ganglion,  or  the  intermediate  cord  of  the  sympa- 
thetic, also  detaches  branches  internally,  which  are  very  small,  and 
more  or  less  interwoven  with  each  other.  These  branches  get  to 
the  abdominal  aorta,  and  joining  the  inferior  mesenteric  plexus  upon 
it,  are  distributed  along  with  the  latter. 

Of  the  Sacral  Ganglions  of  the  Sympathetic. 

There  are  generally  three  of  these  ganglions  which  may  be  readily 
found : sometimes  four  or  five.  They  are  situated  in  a line,  on  the 
anterior  face  of  the  sacrum,  near  the  corresponding  foramina  for  the 


THE  SYMPATHETIC  NERVE. 


521 


transmission  of  the  sacral  nerves ; and  are  united  with  each  other  by 
intermediate  fibres,  from  one  to  three  in  number,  which  are  the  con- 
tinuation of  the  sympathetic  nerve.  Bichat  asserts,  that  frequently 
the  first  of  these  ganglions  is  not  united  to  the  last  of  the  lumbar  by 
an  intermediate  nerve,  so  that  there  the  continuity  of  the  sympathetic 
is  interrupted. 

Each  ganglion  sends  off,  externally,  one  or  more  filaments,  by 
which  it  is  united  to  the  corresponding  sacral  nerve : it  also  de- 
taches filaments  in  this  direction  to  the  pyriformis  and  the  levator 
ani  muscles. 

Each  ganglion  likewise  detaches,  from  its  internal  margin,  rami- 
fications, which  go  obliquely  downwards  on  the  front  of  the  sacrum, 
and  anastomose  with  the  corresponding  filaments  from  the  opposite 
side. 

From  these  ganglions  many  branches  pass  forwards  to  the  hypo- 
gastric plexus;  which  is  formed  by  them,  by  the  inferior  mesen- 
teric plexus,  and  by  a great  many  filaments  from  the  lower  sacral 
nerves,  principally  the  third.  The  plexus  is  distributed  upon  the 
rectum,  the  bladder,  vesiculae  seminales,  and  prostate  of  the  male ; 
and,  in  place  of  the  two  latter  in  the  female,  upon  the  vagina  and 
the  uterus. 

The  last  sacral  ganglion  detaches  downwards  one  or  more  fila- 
ments, which  lie  upon  the  front  of  the  os  coccygis,  and  anastomose 
with  the  corresponding  filaments  from  the  other  side,  to  form  a sort 
of  arch,  the  convexity  of  which  is  downwards.  In  this  manner,  ter- 
minates the  chord  of  the  sympathetic  nerve. 


CHAPTER  III. 

Of  the  Nerves  of  the  Medulla  Spinalis. 

The  nerves  of  the  medulla  spinalis,  with  the  exception  of  the 
first,  which  from  its  position,  is  generally  called  by  anatomists  the 
Sub-occipital,  are  arranged  into  cervical,  dorsal,  lumbar,  and  sacral; 
according  to  the  order  of  the  intervertebral  foramina,  through  which 
Vol.  II.— 45 


522 


NERVOUS  SYSTEM. 


they  pass  out:  but  a much  better  division  would  be  Cervical,* 
Thoracic,  and  Abdominal.  Their  mode  of  origin,  and  the  ganglions 
formed  by  them,  have  been  pointed  out  in  the  account  of  the 
medulla  spinalis. 

<■  * r • 

SECT.  I. — OF  THE  UPPER  NINE  SPINAL  NERVES. f 

These  are  spent  upon  the  neck,  upon  the  upper  extremities,  and 
upon  the  diaphragm.  They  consist  in  the  Sub-occipital  Nerve,  the 
Cervical,  and  the  First  Dorsal. 

Of  the  Sub-occipital  JYerve. 

The  Sub-occipital  Nerve  ( Nervus  Infra-occipitalis , decimus 
cerebri)  is  one  of  the  smallest  that  proceeds  from  the  medulla  spi- 
nalis. It  has  the  peculiarity,  generally,  of  arising  by  a single 
root,  which  comes  from  the  anterior  chord  of  the  medulla  spinalis, 
between  the  occiput  and  the  first  cervical  vertebra.  This  root 
consists  of  from  two  to  six  or  seven  fasciculi,  situated  one  above 
another.  When  the  posterior  root  exists,  it  is  very  small,  is  com- 
posed of  from  one  to  three  fasciculi,  and  anastomoses  with  the  ac- 
cessory nerve. 

The  trunk  of  this  nerve  passes  from  the  vertebral  cavity  through 
the  foramen  formed  in  the  dura  mater  by  the  vertebral  artery ; it 
goes  out  below  the  latter,  and  between  the  occiput  and  the  first  ver- 
tebra, behind  its  superior  oblique  process.  It  there  forms  a small 
long  ganglion,  like  the  other  spinal  nerves,  and  then  divides  into  an 
anterior  and  a posterior  fasciculus. 

The  anterior  fasciculus  is  the  smaller  of  the  two  ; it  follows,  in 
some  measure,  the  course  of  the  vertebral  artery,  and  going  forwards 
to  the  front  of  the  transverse  process,  is  then  divided  into  several  fine 
filaments,  some  of  which  go  to  the  contiguous  muscles  on  the  front 
of  the  vertebrae;  others  join  themselves  to  the  pneumogastric  and 
hypoglossal  nerves,  and  to  the  superior  cervical  ganglion  of  the 
sympathetic ; others  anastomose  with  the  first  cervical  nerve. 

* In  this  case,  the  term  Cervical  would  include  the  first  eight, 
t Anat.  Atlas,  Fig.  620,  621. 


UPPER  NINE  SPINAL  NERVES. 


523 


The  posterior  fasciculus  runs  backwards,  and  is  distributed  to 
the  recti  and  the  obliqui  muscles  on  the  back  of  the  neck,  and  to 
the  complexus. 

Of  the  Cervical  JVerves. 

These  are  seven  in  number:  the  first  one  gets  from  the  spinal 
cavity  between  the  atlas  and  the  dentata;  and  the  last  between  the 
seventh  cervical  and  the  first  dorsal  vertebra.  After  the  ganglion  is 
formed  upon  the  posterior  fasciculus  of  each,  the  ti’unk,  made  by 
the  union  of  the  two  fasciculi,  divides  almost  immediately  again  into 
an  anterior  and  a posterior  trunk. 

Of  the  First  Cervical  JVerve. 

The  posterior  trunk  is  the  largest,  and  goes  directly  backwards. 
It  has  its  filaments  distributed  to  many  of  the  muscles  on  the  upper 
posterior  part  of  the  cervical  vertebrae,  and  to  the  integuments  of 
the  part.  Some  of  the  branches  ascend  through  the  muscles,  near 
the  occiput ; and,  rising  up  on  the  latter,  are  distributed  upon  its 
integuments,  and  upon  the  occipito-frontalis  muscle. 

The  anterior  trunk  is  directed  forwards  under  the  inferior  oblique 
muscle  of  the  neck,  and  then  divides  into  two  branches : the  superior 
joins  the  anterior  branch  of  the  sub-occipital  nerve,  and  anastomoses 
with  the  first  cervical  ganglion  of  the  sympathetic,  and  with  the  par 
vagum  and  the  hypo-glossal  nerve ; the  inferior  joins  the  anterior 
branch  of  the  second  cervical  nerve. 

Of  the  Second  Cervical  JVerve. 

This  nerve  issues  between  the  second  and  the  third  cervical  ver- 
tebra. Its  posterior  trunk  is  spent  upon  the  trapezius,  complexus, 
and  other  muscles  on  the  back  of  the  neck,  and  upon  the  integu- 
ments of  the  latter;  it  also  anastomoses  with  the  posterior  trunk  of 
the  nerve  above  and  below. 

The  anterior  branch  or  trunk  detaches,  first  of  all,  some  small  fila- 
ments to  the  muscles  on  the  front  of  the  cervical  vertebrae ; it  then 


524 


NEKVOUS  SYSTEM. 


divides  into  two  principal  fasciculi,  one  of  which  ascends  and  the 
other  desends. 

The  ascending  branch  goes  upwards  and  backwards,  and  early  in 
its  course  anastomoses  with  the  first  cervical  nerve,  thereby  forming 
with  it  a nervous  noose ; it  then  mounts  upon  the  occiput,  and  is 
distributed  upon  the  parts  on  the  latter  region,  anterior  to  the  occi- 
pital branches  of  the  preceding  nerve. 

The  descending  branch  turns  over*  the  posterior  margin  of  the 
sterno-cleido  mastoideus  muscle,  and  gives  filaments  to  it.  It  is 
distributed  afterwards  by  branches,  some  of  which  go  to  the  inte- 
guments of  the  middle  and  inferior  parts  of  the  neck,  ( nervi  subcu- 
tanei  colli  medii  et  inferiores,)  others  go  the  integuments  of  the  neck 
upon  the  angle  and  the  base  of  the  lower  jaw,  ( nervi  subcutanei 
colli  superiores ,)  and  one  to  the  external  ear,  ( nervus  auricularis 
cervical  is.) 

From  the  anterior  fasciculus  of  the  second  cervical  nerve,  there 
proceeds  a filament  downwards,  v'hich  is  the  upper  root  of  the 
phrenic  nerve;  another  filament  from  it  joins  the  superior  cervical 
ganglion  of  the  sympathetic. 


Of  the  third  Cervical  Nerve. 

This  nerve  comes  out  between  the  third  and  the  fourth  cervical 
vertebra.  Its  posterior  fasciculus  is  distributed  to  the  muscles  on 
the  back  of  the  cervical  vertebrae,  and  to  the  integuments  of  the 
part ; anastomosing,  by  its  branches,  with  the  nerve  above  and 
below. 

The  anterior  fasciculus  is  larger  than  the  posterior,  and  goes  ob- 
liquely downwards  and  outwards  at  first ; it  sends  anastomotic 
branches  to  the  nerve  above  and  below ; it  also  anastomoses  with 
the  superior  cervical  ganglion  of  the  sympathetic  and  with  the  de- 
scendens  noni.  One  of  its  branches,  being  joined  by  the  branch 
just  spoken  of,  from  the  second  cervical  nerve,  constitutes  the  root 
of  the  phrenic  nerve.  But  the  principal  number  of  its  branches  are 
distributed  to  the  integuments  along  the  clavicle,  ( nervi  supra-clavi- 
culares ,)  the  upper  part  of  the  sternum,  and  the  shoulder;  some  of 
them  going  into  the  contiguous  muscles,  as  the  trapezius,  subclavius, 
&c.  Several  anastomoses  exist  between  the  branches  of  this  nerve 
and  the  terminating  branches  of  the  nervus  accessorius. 


PHRENIC  NERVE. 


525 


The  three  preceding  cervical  nerves  form,  by  their  anastomoses 
with  each  other,  a plexus,  consisting  in  a number  of  large  loops  or 
arches,  which  lie  upon  the  sides  of  the  muscles  connected  with  the 
transverse  processes  of  the  cervical  vertebrae.  There  are  commonly 
two  series  of  anastomoses:  the  branches  of  the  first  series,  form  the 
second  series,  and  from  the  latter  proceed,  for  the  most  part,  the 
several  branches  which  have  been  described.  These  anastomoses 
are  covered  by  the  upper  half  of  the  sterno  cleido-mastoid  muscle, 
are  involved  in  the  cellular  membrane  surrounding  the  great  vessels 
of  the  neck,  and  are  covered  by  the  lymphatic  glands.  Their  inter- 
texture and  distribution  are  such,  that  no  adequate  idea  of  them  can 
be  conveyed  without  dissection.  From  this  plexus  several  branches 
go  to  the  sterno-mastoid  muscle;  it  is  united  above  to  the  sub-occi- 
pital nerve,  and  below  to  the  fourth  cervical. 


Of  the  Phrenic  Nerve . 

The  Phrenic  Nerve  ( Nervus  Phrenicus , Diaphragmaticus ) arises,, 
in  the  manner  stated  above,  from  the  anterior  fasciculus  of  the  second 
and  of  the  third  cervical,  and  is  assisted  generally  by  two  or  three 
filaments  from  the  upper  part  of  the  brachial  plexus.  It  descends, 
vertically,  on  the  humeral  side  of  the  internal  jugular  vein,  but  re- 
moved a considerable  distance  from  it,  and  is  attached,  by  cellular 
substance,  to  the  front  of  the  scalenus  anticus  muscle.  Getting,  in 
its  descent,  to  the  internal  margin  of  the  latter,  it  passes  into  the 
thorax,  at  the  inner  margin  of  the  first  rib,  between  the  subclavian 
artery  and  the  subclavian  vein,  the  latter  being  before  it.  It  then 
goes  along  the  superior  mediastinum  to  the  pericardium,  to  the  side 
of  which  it  adheres  in  front  of  the  root  of  the'  lung,  being  between 
the  pericardium  and  the  corresponding  portion  of  the  pleura ; it  finally 
reaches  the  diaphragm,  to  which  it  is  distributed. 

Just  before  the  phrenic  nerve  reaches  the  diaphragm,  it  radiates 
into  several  branches,  which  interchange  filaments.  Some  of  the 
branches  are  distributed  to  the  convex  surface  of  the  diaphragm ; 
others  penetrate  this  muscle,  and  are  distributed  in  its  thickness  and 
upon  its  concave  surface.  On  the  right  side,  some  of  these  branches 
pass  through  the  opening  for  the  ascending  vena  cava,  and  thus. 

45* 


526 


NERVOUS  SYSTEM. 


getting  into  the  abdomen,  anastomose  with  the  solar  plexus,  and 
with  the  pneumogastric  nerve. 

The  phrenic  nerve  of  the  left  side  is  nearer  to  the  root  of  the  lung 
than  that  of  the  right,  in  consequence  of  the  projection  of  the  apex 
ot  the  heart  on  that  side.  Its  distribution  in  other  respects  does  not 
present  any  remarkable  difference  from  the  other ; its  branches  radiate 
in  the  same  way  to  the  diaphragm,  and  supply  its  thickness,  as  well 
as  its  upper  and  under  surfaces.  It  sends  some  filaments  to  the 
lower  part  of  the  oesophagus. 

The  phrenic  gives  off  in  the  neck  a few  filaments  to  the  scalenus 
anticus,  and  the  rectus  anticus  major  muscle.  It  also  communicates 
there,  with  filaments  from  the  inferior  cervical  ganglion,  and  some- 
times from  the  superior  cervical. 


Of  the  Four  Inferior  Cervical  Nerves. 

The  trunks  of  these  nerves,  on  issuing  from  the  intervertebral  fo- 
ramina, have  one  general  mode  of  distribution,  which  permits  them 
to  be  described  together  or  in  common. 

The  posterior  branches  are  much  smaller  than  those  of  the  pre- 
ceding cervical  nerves  ; they  go  backwards  between  the  complexus 
and  the  transversalis  colli,' and  leave  filaments  in  their  passage  with 
them  and  other  muscles:  they  then  reach  the  splenius  and  the  trape- 
zius, to  which  and  to  the  integuments  of  the  neck  they  are  distri- 
buted. 

The  anterior  branches  are  large ; they  appear  on  the  side  of  the 
neck,  between  the  scalenus  anticus  and  medius  muscles  ; sometimes 
perforating  the  substance  of  one  or  the  other  of  these  muscles. 
They  each  detach  filaments  to  the  sympathetic.  The  fourth,  also, 
commonly  sends  one  to  the  phrenic.  They  then  form  the  Brachial 
Plexus. 

Of  the  Brachial  Plexus  and  the  Nerves  of  the  Upper  Extremity.* 

The  Brachial  or  the  Axillary  Plexus  is  formed  by  the  junction  and 
the  intertexture  of  the  four  inferior  cervical  nerves,  and  the  first  dor- 
sal or  thoracic.  It  extends  from  the  scaleni  muscles  to  the  axilla,  on 


* Anat.  Atlas,  Figs.  625,  626,  627. 


NERVES  OF  UPPER  EXTREMITY. 


527 


a level  with  the  neck  of  the  os  humeri.  The  nerves  at  first  converge, 
and  are  situated  somewhat  behind  the  subclavian  artery  where  it 
passes  over  the  first  rib : but  are  at  various  heights  above  it  accord- 
ing to  their  origin,  with  the  exception  of  the  first  dorsal  nerve,  which 
has  to  ascend  in  order  to  pass  out  of  the  thorax. 

The  plexus  is  formed  in  the  following  manner.  The  fourth  and 
the  fifth  cervical  nerves  unite  near  the  scaleni  muscles  into  a single 
trunk,  which  runs  a short  distance  downwards,  and  then  splits  into 
two.  The  seventh  cervical  and  the  first  dorsal  do  the  same.  The 
sixth  cervical  is  the  central  nerve  of  the  plexus,  and  after  going 
downwards  two  or  three  inches,  it  bifurcates  also.  Combinations  of 
these  primary  divisions  are  formed,  which  are  dissolved,  and  then 
reformed,  in  such  a way  that  a complex  intertexture  of  the  original 
nerves  takes  place.  This  intertexture  surrounds  the  axillary  artery 
somewhat  like  the  braids  of  a whip-cord,  from  the  clavicle  to  the  os 
humeri  below  its  head.  In  this  course  the  axillary  plexus  passes 
along  with  the  artery  between  the  subclavius  muscle  and  the  first  rib, 
lies  in  contact  with  the  superior  part  of  the  serratus  major  anticus 
muscle,  and  immediately  below  the  articulation  of  the  shoulder 
joint.  The  axillary  vein  is  in  front  of  it. 

The  nerves  which  proceed  from  the  axillary  plexus  are  the  Sca- 
pular ; the  Thoracic;  the  Axillary;  the  two  Cutaneous;  the  Radial; 
the  Ulnar ; and  the  Median.  They  supply  the  superior  extremity, 
including  the  shoulder  and  the  axilla. 

1.  The  Scapular  Nerve  ( JVervus^  Scapularis , or  Supra- Scapularis) 
is  a small  branch  coming  commonly  from  the  upper  part  of  the 
plexus,  as  formed  by  the  fourth  cervical  nerve.  It  goes  backwards 
in  company  with  the  arteria  dorsalis  superior  scapulae,  through  the 
notch  or  foramen  of  the  upper  costa  of  the  scapula;  and  having  thus 
got  to  the  posterior  face  of  the  latter,  it  gives  filaments  to  the  supra 
spinatus  muscle ; continuing  its  course  then  on  the  posterior  face  of 
the  cervix  scapulae,  it  is  lost  in  filaments  upon  the  infra-spin atus  and 
teres  minor  muscles. 

2.  The  Subscapular  Nerves  ( Nervi  Subscapulares ) of  Bichat  pre- 
sent some  varietes  in  their  origin  ; occasionally  they  come  from  the 
same  trunk,  but  commonly  each  has  its  peculiar  root  from  the  central 
parts  of  the  axillary  plexus.  There  are  generally  three  of  them. 
One  of  them  descends  behind  the  axillary  vessels,  between  the  sub- 


528 


NERVOUS  SYSTEM. 


scapularis  muscle  and  the  serratus  major  anticus  ; it  crosses  the  teres 
major,  and  is  lost  upon  the  contiguous  part  of  the  latissimus  dorsi. 
Another  is  distributed  upon  the  subscapularis  muscle.  The  third 
descends  along  the  anterior  margin  of  the  subscapularis  for  a short 
distance,  and  distributes  filaments  to  it,  to  the  teres  minor  and  major 
muscles. 

3.  The  Thoracic  Nerves  ( Nervi  Thoracici ) are  primarily  two  or 
three  in  number,  and  proceed  from  about  the  middle  of  the  plexus. 
The  fasciculi  into  which  they  are  resolved,  may  be  distinguished  as 
anterior  and  posterior.  The  former  are  distributed  by  filaments,  to 
the  subclavian  muscle,  to  the  pectoralis  minor  and  major,  and  to  the 
integuments  covering  the  latter.  The  posterior  thoracic  has  its 
origin  somewhat  concealed  by  the  scalenus  anticus  muscle.  It  de- 
scends into  the  axilla,  adhering  to  the  serratus  major  muscle  for 
some  distance,  and  is  then  distributed  by  many  filaments  to  this 
muscle. 

4.  The  Axillary  Nerve  ( JVervus  Axillaris , or  Circumflexus ) comes 
from  the  inferior  part  of  the  plexus.  Immediately  after  its  origin,  it 
goes  downwards  and  outwards  over  the  upper  extremity  of  the  sub- 
scapularis muscle.  It  then  winds  around  the  os  humeri,  between, 
the  teres  minor  and  major  muscles,  observing  the  course  of  the  pos- 
terior circumflex  artery,  and,  finally,  terminates  on  the  under  surface 
of  the  deltoid  muscle. 

This  nerve  sometimes  gives  off  the  subscapular  nerves,  and,  in- 
deed, it  is  usual  for  anatomist?  to  include  the  description  of  the 
latter  in  it.  As  it  turns  round  the  bone,  it  divides  into  two  principal 
trunks ; the  superior  goes  to  the  inferior  margin  of  the  infra-spinatus 
and  to  the  posterior  margin  of  the  deltoides  ; the  inferior  is  distri- 
buted principally  in  the  substance  of  the  deltoid  muscle,  but  some  of 
its  filaments,  by  perforating  the  latter,  reach  the  skin,  and  constitute 
the  JVervus  cutaneus  humeri.  Filaments  go  from  the  nervus  axillaris 
in  the  early  part  of  its  course,  to  the  subscapularis  and  the  two  teres 
muscles. 

5.  The  Internal  Cutaneous  Nerve  ( JVervus  Cutaneus  Internus *) 
arises  from  the  lower  part  of  the  axillary  plexus,  and  is  one  of  the 
smallest  of  those  which  go  to  the  arm.  It  is  situated  between  the 

* Antonius  and  Caldani,  Tabul.  CCLVIII. 


NERVES  OF  UPPER  EXTREMITY. 


529 


median  and  the  ulnar  nerve,  and  adheres  almost  as  far  as  the  elbow, 
to  the  basilic  vein.  In  its  descent,  this'  nerve  detaches  several 
small  filaments,  which,  perforating  the  fascia  of  the  arm,  are  distri- 
buted to  the  integuments  of  the  biceps  muscle,  and  to  those  on  the 
internal  face  of  the  triceps. 

Somewhat  above-  the  bend  of  the  elbow,  at  the  place  where  the 
median  basilic  vein  joins  the  basilic,  but  occasionally  some  inches 
higher  up,  the  internal  cutaneous  becomes  superficial,  and  splits  into 
two  branches  of  nearly  equal  magnitude,  which  diverge  but  little 
from  each  other  at  first.  The  branch  nearest  the  internal  condyle  of 
the  os  humeri,  lies  in  front  of  the  basilic  vein,  as  it  passes  over 
the  elbow  joint;  and  continues  in  this  position  for  two  or  three 
inches : it  goes  down  the  front  of  the  fore  arm  on  its  ulnar  side,  but 
inclines  continually  to  the  back  of  the  fore  arm.  In  this  course,  it 
detaches  small  ramifications  to  the  integuments  about  the  internal 
condyle,  and  about  the  heads  of  the  flexor  muscles ; it  also  detaches 
continually,  from  its  sides,  small  filaments  to  the  integuments  of  the 
ulnar  side  of  the  fore  arm  both  anteriorly  and  posteriorly,  some  of 
which  reach  to  the  hand.  The  other,  being  the  anterior,  or  the  ex- 
ternal branch  of  the  internal  cutaneous,  which  is  nearer  the  radius, 
passes  beneath  the  median  basilic  vein,  about  six  lines  from  the 
basilic  ; but,  just  before  it  does  so,  it  detaches  a very  superficial  cu- 
taneous filament,  which  crosses  in  front  of  the  median  basilic  vein 
about  its  middle,  and  is  lost  a little  below  the  bend  of  the  arm. 
The  anterior  or  outer  branch  of  the  internal  cutaneous  having  got 
from  beneath  the  median  basilic  vein,  goes  superficially  as  far  as  the 
middle  of  the  fore  arm  without  sending  off  any  filaments  of  note  ; it 
is  then  divided  successively  into  several,  which  diverge  to  supply 
the  skin  down  to  the  wrist. 

6.  The  Musculo-Cutaneous  Nerve  ( JVervus  Musculo- Culaneiis, 
or  Cutaneus  Externus ,)  is  somewhat  larger  than  the  preceding,  and 
arises  from  about  the  middle  of  the  brachial  plexus.  It  descends  a 
short  distance,  and  then  perforates  obliquely  the  upper  part  of 
the  coraco-brachialis  muscle.  Having  passed  through  this  muscle, 
it  continues  its  course  obliquely,  between  the  brachialis  internus 
and  the  biceps  flexor,  and,  finally,  makes  its  appearance  super- 
ficially on  the  outer  side  of  the  tendon  of  the  latter.  In  this  course, 
it  distributes  filaments  to  the  several  muscles  with  which  it  is  con- 
nected. 


530 


NERVOUS  SYSTEM. 


It  afterwards  passes  the  elbow  joint  under  the  median  cephalic 
vein  near  its  middle,  and  descends  between  the  skin  and  the  fascia 
of  the  fore  arm,  near  the  outer  margin  of  the  median  vein,  to  the 
hand : in  this  course,  it  is  parallel  with  and  on  the  front  of  the  supi- 
nator radii  longus.  It  distributes  many  filaments  to  the  correspond- 
ing integuments  on  the  radial  side  of  the  fore  arm,  and,  having  at 
length  got  near  the  lower  end  of  the  radius,  it  divides  into  two  orders 
of  fibres,  one  of  which  is  distributed  to  the  integuments  on  the  dorsal, 
and  the  other  to  those  on  the  palmar  side  of  the  hand,  about  the  root 
of  the  thumb. 

7.  The  Radial  Nerve  ( JVervus  Radialis , or  Musculo-Spiralis ,)  arises 
from  the  upper  portion  of  the  brachial  plexus,  but  in  such  a way, 
that  filaments  from  almost  every  part  of  the  latter  run  into  it.  It 
is  a large  trunk  which  winds  spirally  around  the  os  humeri,  between 
the  triceps  muscle  and  the  bone,  by  entering  the  fissure  between  the 
first  and  the  third  head  of  the  triceps.  It  appears  on  the  outside 
of  the  os  humeri,  between  the  brachialis  interims  and  the  triceps 
muscle  ; running  for  some  inches  in  contact  with  their  intermuscular 
ligament.  While  beneath  the  triceps,  it  sends  several  branches  to 
its  heads.  There  are  three  principal  trunks  afterwards  from  this 
nerve. 

a.  The  Ramus  Superficialis  Dorsalis  is  sent  from  it  on  a line 
with  the  point  of  the  deltoid  muscle.  This  branch  then  goes  just 
below  the  skin,  parallel  with  and  over  the  external  ridge  of  the  os 
humeri;  it,  of  course,  crosses  the  origin  of  the  muscles  of  the  ex- 
ternal condyle.  It  continues  superficial  on  the  posterior  external 
edge  of  the  supinator  radii  longus  muscle,  and  terminates  in  the  in- 
teguments on  the  back  of  the  hand. 

The  continued  trunk  of  the  muscular  spiral  goes  in  the  interstice 
between  the  extensor  muscles,  and  the  brachialis  interims,  and,  at 
the  external  condyle,  divides  into  the  other  two  branches,  from 
which  filaments  proceed  to  the  contiguous  heads  of  the  muscles. 

b.  The  Ramus  Profundus  Dorsalis  perforates  the  supinator  brevis 
muscle,  getting  beneath  the  radial  extensors  to  the  back  of  the 
fore  arm : it  is  then  distributed  in  numerous  filaments  to  the  muscles 
on  the  back  of  the  fore  arm,  some  of  its  branches  reaching  to  the 
wrist. 

c.  The  Ramus  Superficialis  Anterior  seems  to  be  a continuation 
of  the  main  trunk  of  the  nerve,  and  descending  at  the  anterior  mar- 
gin of  the  supinator  radii  longus  muscle,  it  joins  with  the  radial 


NERVES  OF  UPPER  EXTREMITY. 


531 


artery  and  continues  in  its  company  to  a short  distance  below  the 
middle  of  the  radius.*  Here  it  crosses  the  bone  obliquely  beneath 
the  tendon  of  the  supinator  longus,  and  then  divides  into  a palmar 
and  a dorsal  ramuscule:  the  first  being  distributed  to  the  muscles  and 
integuments  of  the  thumb,  the  second  terminating  so  as  to  supply  the 
back  of  the  hand,  of  the  thumb,  fore,  middle,  and  ring  fingers  to 
their  extremities. 

8.  The  Median  Nerve  ( JVervus  Medianus)  descends  the  arm  at 
the  inner  edge  of  the  biceps  muscle  ; along  the  anterior  surface  of 
the  brachial  artery,  adhering  firmly  to  it,  and  the  deep-seated  veins, 
by  cellular  substance.  As  far  as  the  elbow,  it  sends  off  no  branch 
of  importance.  There  it  lies  at  the  side  of  the  biceps  tendon, 
crosses  the  lower  part  of  the  brachialis  internus,  and  is  beneath  the 
aponeurosis  of  the  biceps.  It  then  perforates  the  pronator  teres  and 
gets  between  the  flexor  sublimis  digitorum,  and  the  flexor  longus 
pollicis,  and  enters  the  palm  of  the  hand  under  the  ligament  of  the 
wrist,  at  the  radial  edge  of  the  tendons  of  the  flexor  sublimis.  In 
the  palm  it  is  situated  beneath  the  aponeurosis  palmaris  and  the 
arcus  sublimis  of  the  arteries. 

The  median  nerve  dispenses  the  following  branches  : — At  the  bend 
of  the  arm,  it  furnishes  filaments  to  the  heads  of  the  first  layer  of 
muscles  of  the  fore  arm ; and  a little  below,  it  detaches  the  Nervus 
Interosseus,  which  supplies  filaments  to  the  flexor  longus  pollicis 
and  flexor  profundus  digitorum.  The  interosseous  nerve  then  de- 
scends with  the  interosseous  artery,  in  front  of  the  interosseous  liga- 
ment, and  terminates  in  the  pronator  quadratus. 

Before  the  median  nerve  reaches  the  wrist,  it  sends  a branch 
which  supplies  with  filaments  the  muscles  and  integuments  of  the 
ball  of  the  thumb.  In  the  palm  of  the  hand,  it  divides  and  sub- 
divides so  as  to  send  a branch  to  each  side  of  the  thumb,  of  the  fore, 
and  of  the  middle  finger,  and  to  one  side  of  the  ring  finger.  These 
branches  go  along  with  the  arteries  to  the  ends  of  the  fingers  and 
thumb. 

9.  The  Ulnar  Nerve  ( JVervus  Ulnaris)  comes  from  the  lowest 
section  of  the  brachial  plexus.  It  descends  along  the  internal  ante- 
rior part  of  the  triceps  muscle,  in  a groove  formed  between  it,  and 


* This  position  gives  the  whole  nerve  the  name  of  radial. 


532 


THE  BALL  OF  THE  EYE. 


the  intermuscular  ligament : it  diverges  in  this  course  gradually  from 
the  median  nerve  till  it  reaches  the  elbow,  when  it  is  at  its  greatest 
point  of  separation.  At  the  elbow,  it  is  behind  the  internal  condyle, 
in  the  groove  between  it  and  the  olecranon,  and  separates  the  two 
heads  of  the  flexor  ulnaris  muscle.  It  then  gets  to  the  fore  arm  be- 
tween this  muscle  and  the  flexor  profundus  digitorum,  and  continues 
between  them  to  within  two  inches  of  the  wrist  joint,  when  it  de- 
taches the  Ramus  Dorsalis. 

The  Ramus  Dorsalis  dips  between  the  ulna  and  the  tendon  of 
the  flexor  ulnaris,  runs  along  the  internal  margin  of  the  ulna  to  the 
carpus  ; it  then  divides  into  ramuscules,  which  supply  the  ulnar  side 
of  the  integuments  on  the  back  of  the  hand,  and  on  the  backs  of 
the  last  two  fingers.  At  the  interval  behind,  between  the  heads  of 
the  metacarpal  bones  of  the  middle  and  ring  fingers,  a considerable 
ramuscule  joins  one  from  the  branch  of  the  muscular  spiral  nerve, 
which  attended  the  radial  artery. 

The  Ulnar  Nerve,  having  given  off  this  dorsal  branch  descends 
along  the  radial  margin  of  the  tendon  of  the  flexor  ulnaris  and  the 
os  pisiforme,  above  the  annular  ligament,  to  the  palm  of  the  hand. 
Getting  beneath  the  aponeurosis,  it  there  detaches  first  a deep- 
seated  branch,  which  penetrates  the  muscles  of  the  little  finger  to 
supply  them,  the  interossei,  and  the  short  flexor  of  the  thumb.  The 
ulnar  nerve  then  furnishes  a superficial  branch,  and  afterwards 
divides  into  three ; one  for  the  ulnar  side  of  the  little  finger,  another 
for  the  opposing  sides  of  the  little  and  ring  finger,  and  a third  which 
joins  the  most  internal  digital  branch  of  the  median  nerve. 

Attached  to  some  of  the  nerves,  but  in  an  especial  degree  to  the 
digital  branches  in  the  hands  and  feet,  are  numerous  small  bodies, 
called  from  their  discoverer  Pacinian.*  They  are  of  an  elliptical 
shape,  appended  by  a pedicle ; are  about  a line  long  and  half  a 
line  wide;  and  consist  in  a series  of  capsules  from  forty  to  sixty, 
one  within  the  other,  with  a cavity  in  the  central  one.  Each  cor-? 
puscle  is  furnished  with  a nervous  filament  reaching  it  through  the 
pedicle,  and  coming  to  a single  or  bifid  end  in  the  central  cavity. 
They  are  considered  by  their  discoverer  as  electrical  organs. 

* Discovered  in  1830.  See  Nuovo  organi  scoperta,  &c.,  da  Felipo  Pacini,  1840. 
Iienle  and  Kolliker  on  the  Pacinian  Corpuscles.  Zurich,  1844.  Br.  and  for.  Med. 
Review.  January  1845. 


THORACIC  SPINAL  NERVES. 


533 


S£CT.  II. — OF  THE  THORACIC  SPINAL  NERVES.* 

The  Dorsal  or  Thoracic  Spinal  Nerves  (, JVervi  Thor  acid,  Dor* 
sales)  consist  in  twelve  pairs,  the  first  pair  goes  through  the  inter- 
vertebral foramen,  between  the  first  and  the  second  dorsal  vertebra, 
and  the  twelfth  pair  between  the  last  dorsal  and  the  first  lumbar  ver- 
tebra. The  common  trunk,  formed  after  the  ganglion  of  each  nerve, 
goes  but  a short  distance  when  it  divides  into  an  anterior  and  a pos- 
terior branch. 

The  Posterior  Branch  ( Ramus  Dorsalis)  of  each  nerve,  goes  back- 
wards between  the  transverse  processes  of  the  corresponding  verte- 
brae, and,  having  got  beneath  the  multifidus  spinse,  is  commonly 
subdivided  into  internal  and  external  ramuscules.  The  internal  are 
the  smaller,  and  are  distributed  upon  the  muscles  lying  upon  the 
spine,  as  the  multifidus,  the  sacro-lumbalis,  longissimus  dorsi,  and 
so  on : their  terminating  filaments  reach  the  skin.  The  external 
branches  descend  obliquely  outwards  beneath  the  longissimus  dorsi, 
and  then  issue  between  the  latter  and  the  sacro-lumbalis,  to  both  of 
which  they  dispense  filaments:  they  afterwards  are  divided  into 
branches,  which  go  to  the  trapezius,  latissimus  dorsi,  rhomboideus, 
and  to  the  corresponding  integuments. 

The  Anterior  Branches  of  the  Dorsal  Nerves  ( Rami  Subcostales) 
correspond  -with  the  intercostal  spaces  of  the  ribs.  Each  one,  in 
a short  course  after  its  origin,  applies  itself  to  the  rib  just  above  it, 
and  accompanies  the  intercostal  vessels  in  the  groove,  formed  in  the 
under  margin  of  each  rib.  After  it  proceeds  about  one-half  or  two- 
thirds  of  the  length  of  the  rib,  it  separates  gradually  from  it,  and 
goes  nearer  the  middle  of  the  intercostal  space  and  the  superior  mar- 
gin of  the  rib  below.  To  the  angle  of  the  rib,  each  nerve  is  only 
covered  in  front  by  the  pleura,  but  afterwards  it  goes  between  the 
intercostal  muscles.  Near  the  sternum,  the  branches  become  super- 
ficial by  escaping  from  between  the  intercostal  muscles,  and  are  dis- 
tributed upon  the  pectoral  muscles,  and  the  adjacent  skin.  These 
terminating  branches  of  the  five  or  six  inferior  dorsal  nerves  go  to 
the  upper  portions  of  the  abdominal  muscles  and  their  integuments. 

* Anat.  Atlas,  Fig,  624. 

Vol.  II. — 46 


534 


NERVOUS  SYSTEM. 


Not  far  from  its  origin,  each  dorsal  nerve  anastomoses  with  the  gan- 
glion or  chord  of  the  sympathetic,  after  the  manner  described  in  the 
account  of  the  latter  nerve.* 

There  are  some  differences  between  the  thoracic  nerves  in  their 
manner  of  distribution. 

The  anterior  fasciculus  of  the  First,  as  mentioned,  forms  the  lower 
part  of  the  axillary  plexus  by  joining  itself  to  the  seventh  cervical. 
It  sends  out,  however,  a subcostal  branch  which  goes  along  the  in- 
ferior face  of  the  first  rib,  supplying  its  intercostal  muscles  and  having 
the  general  distribution  alluded  to. 

The  Second  Subcostal  Branch,  besides  the  common  distribution, 
detaches  a fasciculus,  which,  penetrating  between  the  ribs,  gets  into 
the  axilla,  and  is  augmented  by  a branch  from  the  internal  cutaneous 
nerve  of  the  upper  extremity.  It  then  descends  along  the  internal 
posterior  face  of  the  arm  to  the  elbow,  and  in  this  course  detaches 
several  fine  filaments  to  the  integuments. 

The  Third  Subcostal  Branch  in  like  manner  detaches  an  axillary 
fasciculus  which  goes  to  the  inferior  part  of  the  arm-pit,  to  the  in- 
teguments of  which,  and  to  those  on  the  internal  face  of  the  arm,  it 
is  distributed.  It  does  not  descend  quite  so  low  as  the  preceding. 
These  two  nerves  are  called  Intercosto-Humeral,  and  from  their 
origin  and  course,  are  supposed  to  account  for  the  numbness  of  the 
arm,  in  cases  of  Angina  pectoris. 

The  Fourth,  Fifth,  Sixth,  and  Seventh  Subcostal  Branches  of  the 
Dorsal  or  Thoracic  Nerves,  about  the  middle  of  the  ribs  to  which 
they  respectively  belong,  are  all  divided  into  two  branches.  One  of 
them,  which  is  properly  speaking  the  Intercostal , continues  in  the 
intercostal  space,  giving  filaments  to  its  muscles  and  to  the  triangu- 
laris sterni ; it  then  emerges  near  the  sternum  to  terminate  upon  the 
great  pectoral  muscle,  the  mamma,  and  the  integuments  of  the  front 
of  the  thorax.  The  other  branch  is  the  External  pectoral : it  ex- 
tricates itself  earlier  from  the  intercostal  space  and  is  distributed 
upon  the  muscles  and  the  integuments  on  the  side  of  the  thorax. 

* It  is  observed  in  pleuritis,  that  there  is  a deposite  of  lymph,  mixed  with  the 
cellular  adipose  matter,  surrounding  the  Sympathetic,  its  costal  branches,  and  the 
subcostal  nerves  until  the  latter  get  between  the  intercostal  muscles.  This  inflamed 
stite  must,  no  doubt,  produce  particular  nervous  phenomena  ; as  pain,  difficulty  of 
respiration,  and  derangement  of  the  functions  of  the  abdominal  viscera. 


ABDOMINAL  SPINAL  NERVES. 


535 


The  remaining  subcostal  branches,  to  the  eleventh  inclusively, 
have  very  much  the  same  principle  of  distribution.  Their  inter- 
costal fasciculi,  having  reached  the  anterior  ends  of  the  intercostal 
spaces,  pass  on  to  the  abdominal  parietes,  between  the  transversalis 
muscle  and  the  internal  oblique,  to  both  of  which  they  give  fila- 
ments. They  reach  the  external  margin  of  the  rectus  abdominis 
muscle,  and  then  divide  into  filaments,  some  of  which  go  to  this 
muscle,  others  pierce  the  fore  part  of  its  sheath  and  are  ramified 
upon  the  integuments  of  the  front  of  the  abdomen. 

The  Twelfth  Subcostal  Branch  of  the  Dorsal  Nerves,  sends  first 
a branch  downwayds,  which  joins  with  the  first  lumbar  nerve.  It 
then  crosses  in  front  of  the  quadratus  lumborum  muscle,  to  which  it 
gives  filaments  as  wrell  as  to  the  adjoining  portion  of  the  diaphragm. 
It  afterwards  divides  into  two  branches,  the  superior  of  which  goes 
for  some  distance  between  the  two  oblique  muscles  of  the  abdomen, 
detaching  filaments  to  them,  and  finally  terminates  on  the  integu- 
ments of  the  abdomen:  the  other  branch  goes  between  the  trans- 
versalis and  the  internal  oblique,  and  is  extended  to  the  lower  part 
of  the  rectus,  and  to  the  pyramidalis  muscle,  to  all  of  which  it  dis- 
tributes filaments. 


SECT.  III. — OF  THE  ABDOMINAL  SPINAL  NERVES.* 

There  are  five  lumbar,  and  five  sometimes  six  sacral  nerves  on 
each  side  ; the  first  of  them  passes  out  of  the  intervertebral  foramen, 
between  the  first  and  the  second  lumbar  vertebra  ; and  the  remaining 
lumbar  and  sacral-nerves  go,  successively,  through  the  foramina  in 
the  loins  and  in  the  sacrum. 

The  anterior  fasciculi  of  these  nerves  form  a plexus  which  ex- 
tends from  the  upper  part  of  the  loins  to  the  lower  part  of  the  sa- 
crum : it  is  designated  under  the  general  term  of  Plexus  Cruralis. 
The  posterior  fasciculi  are  much  smaller.  Those  of  the  loins  go 
backwards  between  the  transverse  processes,  and  are  distributed 
upon  the  sacro-lumbalis,  the  longissimus  dorsi,  the  multifidus  spinse, 
and  the  corresponding  integuments.  The  posterior  fasciculi  of  the 
sacral  nerves  are  not  so  large,  generally,  as  those  of  the  lumbar : 
they  get  out  through  the  foramina,  on  the  posterior  face  of  the  sacrum; 


* Anat.  Atlas,  Fig.  628. 


536 


NERVOUS  SYSTEM. 


are  distributed  to  the  same  muscles,  to  the  origin  of  the  glutgeus 
magnus,  and  to  the  integuments  of  the  sacrum,  and  of  the  adjoining 
portion  of  the  buttocks. 

The  Plexus  Cruralis,  for  the  purpose  of  description,  has  been  di- 
vided by  anatomists  into  the  Plexus  Lumbalis,  formed  by  the  four 
superior  lumbar  nerves,  and  the  Plexus  Ischiadicus,  formed  by  the 
last  lumbar  and  the  sacral  nerves. 

The  Lumbar  Plexus  ( Plexus  Lumbalis)  is  concealed  by  the  psoas 
magnus  muscle,  and  is  placed  between  it,  the  lumbar  vertebrae, 
and  the  quadratus  lumborum.  Frequently  the  roots  of  the  nerves 
forming  this  plexus  penetrate  through  the  substance  of  the  psoas 
magnus,  and  form  their  unions  in  it.  The  plexus  is  narrow  and 
pointed  above,  where  it  commences  by  the  fasciculus  of  the  last 
dorsal  nerve  joining  the  first  lumbar ; but  it  increases  continually 
afterwards  in  breadth,  owing  to  the  nerves  composing  it,  succes- 
sively anastomosing  farther  and  farther  from  the  spinal  column. 
From  this  plexus  proceed  three  principal  trunks : the  upper  one  the 
Anterior  Crural  {Cruralis  Anterior)  is  of  considerable  size  ; and  goes 
to  the  skin  and  the  muscles  on  the  front  of  the  lower  extremity ; the 
middle,  called  Obturator  ( JVervus  Obturatorius ,)  is  not  so  large  as 
the  preceding,  and  goes  through  the  obturator  foramen  to  the  ad- 
ductor muscles  of  the  thigh;  the  inferior  formed  by  the  whole  of  the 
fifth  and  a fasciculus  from  the  fourth  lumbar  nerve,  joins  the  upper 
part  of  the  Plexus  Ischiadicus  in  the  pelvis.  Besides  these,  there  are 
several  branches  of  smaller  size  and  of  less  importance,  proceeding 
from  the  lumbar  plexus.  As  follows: — 

The  Abdomino-  Crural  Branches , which  accordingto  Bichat,  are  most 
commonly  three  in  number,  and  come  from  the  two  upper  lumbar 
nerves.  The  first  of  them  goes  obliquely  downwards  and  outwards, 
in  front  of  the  quadratus  lumborum,  to  the  posterior  part  of  the  spine 
of  the  ilium,  and  runs  for  a short  distance  along  the  crista  of  the 
bone  : it  gives  filaments  to  the  iliacus  interims,  and  to  the  abdominal 
muscles,  where  they  border  upon  this  part  of  the  bone.  Some  of 
the  filaments  become  cutaneous,  but  the  main  trunk  of  the  nerve 
reaches  the  anterior  superior  spinous  process,  by  going  between  the 
transversalis  and  the  internal  oblique  muscle ; it  then  follows  the 
inguinal  arch  to  the  external  ring,  through  which  it  passes,  and  is 
distributed  in  filaments  upon  the  groin,  the  pubes,  and  the  scrotum. 
The  second  or  middle  branch  arises  from  the  plexus  near  the  pre- 
ceding; it  descends  along  the  external  margin  of  the  psoas  magnus, 


NERVES  OF  LOWER  EXTREMITY. 


537 


and  crosses  the  iliacus  internus,  covered  by  the  peritoneum;  near 
the  anterior  superior  spinous  process,  it  gets  between  the  lower 
margins  of  the  abdominal  muscles,  and  is  distributed  upon  them 
there : some  of  its  ramifications  get  also  through  the  external  ring, 
and  maybe  traced  to  the  scrotum.  The  third,  or  the  inferior  branch, 
arises  from  the  plexus  still  lower  down,  and  after  having  traversed 
the  front  of  the  iliacus  internus,  it  emerges  from  the  pelvis  beneath 
Poupart’s  ligament,  near  the  anterior  superior  spinous  process;  it 
then  divides  into  filaments  which  penetrate  to  the  skin  through  the 
femoral  fascia,  and  are  distributed  along  the  external  anterior  face  of 
the  thigh: — 

The  Spermaticus  Externus  which  arises  from  the  upper  part  of  the 
plexus,  by  a fasciculus  from  the  first  lumbar  nerve,  which  is  increased 
by  one  from  the  second  lumbar.  It  descends  at  first  in  the  body  of 
the  psoas  magnus  muscle  and  then  in  front  of  it : it  crosses  the  iliacus 
internus,  somewhat  above  Poupart’s  Ligament,  by  directing  its  course 
towards  the  anterior  superior  spinous  process  of  the  ilium.  Here,  it 
involves  itself  in  the  edge  of  the  abdominal  muscles,  and  goes  on 
the  posterior  face  of  Poupart’s  Ligament.  At  the  internal  abdominal 
ring  it  joins  the  spermatic  chord  of  the  male,  or  the  round  ligament 
of  the  uterus  of  the  female.  In  the  first  case,  it  is  distributed  to  the 
spermatic  chord  and  scrotum ; in  the  second,  to  the  labium  externum 
and  mons  veneris.  And  :• — 

The  Cutaneus  Externus  which  arises  from  the  lumbar  plexus  below 
the  external  spermatic.  It  passes  across  the  iliacus  internus  to- 
wards the  anterior  superior  spinous  process,  about  an  inch  below 
the  spermaticus  externus,  and  crosses  the  latter  nerve  just  at  that 
process.  Emerging  from  the  abdomen,  by  penetrating  the  com- 
mencement of  Poupart’s  Ligament,  it  is  distributed  in  several 
branches  to  the  integuments  of  the  vastus  externus  muscle,  and 
along  the  edge  of  the  rectus  femoris : one  of  the  latter  extends  to 
the  patella. 

The  Cutaneus  Medius  is  detached  from  the  Anterior  Crural,  an 
inch  or  so  above  Poupart’s  Ligament.  It  arises  among  the  cluster 
of  branches,  which  come  off  there  to  be  distributed  to  the  iliacus 
internus  muscle,  and  to  the  muscles  of  the  thigh.  It  appears, 
superficially,  on  the  thigh,  for  the  first  time,  by  penetrating  the 

46* 


53S 


NERVOUS  SYSTEM. 


sartorius  muscle,  about  the  internal  edge  of  the  rectus  femoris  ; it 
descends  then  along  the  same  edge  of  the  latter  muscle,  and  is  dis- 
tributed to  its  integuments.  It  does  not  descend  so  low  as  the  ex- 
ternal cutaneous. 

The  Cutaneus  Anterior  arises,  also,  from  the  anterior  crural  nerve. 
It  is  on  the  inner  side  of  the  cutaneus  medius,  emerges  from  the 
fascia  of  the  thigh,  and  crosses  the  sartorius  muscle  two  or  three 
inches  below  the  cutaneus  medius.  It  is  distributed  on  the  integu- 
ments of  the  vastus  internus  muscle,  and  some  of  its  branches  extend 
to  the  internal  edge  of  the  patella. 

The  Cutaneus  Internus  arises  from  the  anterior  crural  nerve,  among 
the  same  cluster,  above  Poupart’s  Ligament.  It  divides  into  four 
or  five  branches  of  different  lengths,  and  is  distributed  to  the  integu- 
ments of  the  adductor  muscles,  and  along  the  inner  front  side  of  the 
thigh.  One  branch  observes  very  much  the  course  of  the  tendon  of 
the  adductor  magnus,  and  reaches  as  far  down  as  the  inner  side  of 
the  knee. 

The  Anterior  Crural*  ( Cruralis  Anterior ) arises  from  the  middle 
of  the  lumbar  plexus : at  first,  it  is  beneath  the  psoas  magnus  mus- 
cle ; it  then  gets  to  its  outside,  and  passes  from  the  abdomen,  under 
Poupart’s  Ligament,  about  half  an  inch  from  the  outside  of  the 
femoral  artery.  Before  it  reaches  Poupart’s  Ligament,  it  gives  off 
a cluster  of  nerves,  several  of  which  go  to  the  iliacus  internus  muscle  ; 
others  form  the  superficial  or  cutaneous  nerves  of  the  thigh  just  men- 
tioned ; and  others,  the  deep-seated  or  muscular  branches,  which 
supply  the  adductor  muscles  of  the  thigh,  its  four  extensors,  the 
pectineus,  the  sartorius,  and  the  gracilis. 

One  of  the  branches  of  the  anterior  crural  nerve  is  seen  to  ac- 
company the  femoral  artery,  till  the  artery  penetrates  the  adductor 
magnus ; it  then  runs  along  the  front  margin  of  the  tendon  of  the 
adductors  in  a theca  formed  by  this  tendon  and  the  origin  of  the 
vastus  internus.  The  nerve  alluded  to  is  the  Saplienus ; it  passes 
afterwards  between  the  internal  condyle  of  the  os  femoris  and  the 
sartorius  muscle,  attaches  itself  to  the  saphena  vein,  and  is  distri- 


* Anat,  Atlas,  Fig.  630. 


NERVES  OF  LOWER  EXTREMITY. 


539 


buted  to  the  integuments  of  the  inner  side  of  the  leg,  and  of  the 
upper  internal  parts  of  the  foot. 

The  Obturator  ( JVervus  Obturatorius ) is  derived  from  the  middle 
of  the  lumbar  plexus,  also ; and  has  very  much  the  same  position,  in 
regard  to  the  psoas  magnus,  as  the  anterior  crural  nerve.  It  descends 
into  the  pelvis  from  beneath  the  psoas  magnus,  near  the  sacro-iliac 
articulation;  and  passes  forwards  and  downwards  to  the  obturator 
foramen;  having  got  through  which,  it  divides  into  an  anterior  and 
a posterior  branch.  The  first  is  distributed  to  the  head  of  the  ad- 
ductor longus  and  brevis,  and  to  the  gracilis  and  integuments.  The 
second  terminates  in  the  obturator  externus,  and  the  adductor 
magnus. 

The  Sciatic  Plexus  ( Plexus  Ischiadicus)*  is  formed  by  the  union 
of  the  last  lumbar  with  the  four  upper  sacral  nerves ; the  last  lumbar, 
before  it  joins  the  plexus,  receives  the  branch  of  the  fourth  lumbar 
nerve,  which  is  left  after  the  lumbar  plexus  is  formed.  This  plexus 
is  situated  at  the  side  of  the  rectum  before  the  pyriformis  muscle. 

The  volume  of  the  posterior  branches  of  the  Sacral  Nerves  in- 
creases till  the  fourth;  but  the  fifth  and  the  sixth  are  much  smaller, 
in  fact  only  fibrillse. 

The  anterior  branches  of  the  sacral  nerves  are  much  larger  than 
the  posterior.  The  first  four  communicate  with  the  sacral  ganglions 
of  the  great  sympathetic,  besides  forming  the  sciatic  plexus.  They 
assist  the  sympathetic,  to  form  the  hypogastric  plexus.  The  fifth, 
and  the  sixth  when  it  exists,  are  distributed  to  the  coccygeus, 
sphincter,  and  levator  ani. 

The  following  small  branches  go  from  the  Sciatic  Plexus. f 

The  JYervi  Glided:  one  passes  through  the  upper  part  of  the  sciatic 
notch  along  with  the  gluteal  artery,  to  the  glutaeus  medius  and  mi- 

* Anat.  Atlas,  Fig.  628. 

t This  is  only  given  as  the  most  frequent  arrangement  of  the  Sciatic  plexus,  and 
of  the  branches  of  nerves  which  proceed  from  it ; other  arrangements  will  often  be 
met  with  in  the  cavity  of  the  pelvis,  in  which  not  so  many  sacral  nerves  are  sent  to 
the  plexus  ischiadicus;  and  the  several  branches  proceeding  from  it  depart  in  a diffe- 
rent manner. 

The  small  branches  described  sometimes  come  from  a common  trunk,  called,  in 
such  case,  the  Small  Sciatic. 


540 


NERVOUS  SYSTEM. 


niraus  muscles ; another  below  the  pyriformis  muscle  to  the  gluteus 
magnus. 

The  JYervus  Pudendalis  Longus  Inferior , when  it  exists,  but  it  is 
frequently  deficient,  passes  under  the  tuber  of  the  ischium  to  the 
glutaeus  magnus;  perineal  muscles;  urethra  and  integuments  of  the 
penis  and  scrotum  in  men ; and  to  the  inferior  parts  of  the  labium 
externum  in  women. 

The  JYervus  Pudendalis  Longus  Superior  comes  from  about  the 
third  and  fourth  sacral.  It  goes  in  company  with  the  internal  pudic 
artery  between  the  sacro-sciatic  ligaments,  and  then  divides  into  two 
branches ; the  inferior  is  distributed  to  the  integuments  and  muscles 
of  the  perineum,  to  the  urethra  and  scrotum ; the  superior  passing 
along  the  ramus  of  the  ischium  and  pubes  with  the  trunk  of  the  in- 
ternal pudic  artery,  is  distributed  to  the  obturator  internus,  accele- 
rator u rinse,  urethra,  and  afterwards,  getting  between  the  symphysis 
of  the  pubes  and  the  penis,  terminates  on  its  integuments  above  and 
on  the  glans  penis. 

The  Ramus  Femoralis  Cutaneus  Posterior.  This  nerve  is  placed 
between  the  integuments  of  the  thigh  and  the  muscles  which  arise 
from  the  tuberosity  of  the  ischium.  It  sends  many  branches,  suc- 
cessively, to  the  skin  on  the  back  of  the  thigh ; one  of  its  branches, 
longer  than  the  others,  goes  down  to  the  ham,  and  there  divides 
into  several  filaments,  which  are  distributed  to  the  integuments  on 
the  back  of  the  leg. 

The  JYervus  Ischiadicus  * or  the  Great  Sciatic,  is  the  common 
trunk,  formed  from  the  sciatic  plexus ; it  is  much  the  largest  nerve 
in  the  body,  and  passes  from  the  pelvis  between  the  pyriformis  and 
the  geminus  superior.  It  crosses  vertically,  the  small  rotator  muscles 
of  the  thigh,  being  concealed  by  the  inferior  edge  of  the  gluteus 
magnus ; it  is  there  about  half-wTay  between  the  tuberosity  of  the 
ischium  and  the  trochanter  major.  Thence  it  descends  on  the  back 
of  the  adductor  magnus,  at  the  outer  edge  of  the  long  head  of  the 
biceps  flexor  cruris.  About  half  way  down  the  thigh,  sometimes  a 
little  low'er,  the  Sciatic  Nerve  divides  into  the  Popliteal,  or  Posterior 
Tibial,  and  the  Peroneal.  Occasionally  this  division  takes  place  as  high 
as  the  exit  of  the  nerve  from  the  pelvis ; but  in  this  case  the  fasciculi 


Anat.  Allas,  Fig.  629. 


NERVES  OF  LOWER  EXTREMITY. 


541 


are  parallel  with  each  other  as  far  as  the  middle  of  the  thigh.  From 
the  trochanter  minor  to  its  usual  place  of  division,  this  nerve  is  parallel 
with,  and  on  the  back  of  the  thigh  bone  ; afterwards  the  two  branches 
begin  to  diverge.  The  popliteal  nerve  continues  straight  downwards 
to  the  back  and  middle  of  the  knee-joint,  and  to  the  interstice  be- 
tween the  heads  of  the  gastrocnemius  muscle ; whereas  the  peroneal 
nerve  goes  along  the  inner  posterior  edge  of  the  biceps  flexor  cruris, 
and  passes  between  its  tendinous  insertion  and  the  external  head  of 
the  gastrocnemius  muscle. 

In  this  course,  the  following  branches  are  sent  from  the  sciatic. — 
Twigs  to  the  little  rotator  muscles  of  the  thigh. — The  Cutaneus 
Internus  Superior,  which  arises  near  the  upper  part  of  the  thigh,  and 
is  distributed  to  the  skin  of  the  corresponding  part. — The  Cutaneus 
Internus  Inferior,  which  arises  just  below  the  last,  and,  descending 
upon  the  inner  head  of  the  gastrocnemius,  is  distributed  to  the  inte- 
guments of  the  calf  of  the  leg. — A large  trunk,  and  sometimes, 
instead  of  it,  distinct  branches  which  go  to  the  Adductor  Magnus, 
Semi-membranosus,  Biceps  and  Semi-tendinous. 

The  Peroneal  Nerve*  ( JVervus  Peroneus ) divides  at  the  head  of  the 
fibula  into  two  branches,  the  Peroneus  Externus  and  the  Tibialis 
Anterior ; but,  before  this  division,  it  sends  a small  branch  to  the 
external  parts  of  the  knee  joint,  and  two  cutaneous  branches  called 
Peroneo-Cutaneous.  Of  these  the  Internal  Peroneo-Cutaneous  de- 
scends behind  the  external  head  of  the  gastrocnemius,  and,  at  the 
bottom  of  the  leg,  is  united  to  a division  of  the  posterior  tibial  called 
the  External  Saphenous,  or  Communicans  Tibiae.  The  External 
Peroneo-Cutaneous  is  distributed  to  the  skin,  along  the  fibula. 

The  External  Peroneal  Nerve  ( Peroneus  Externus ) gets  between 
the  head  of  the  peroneus  longus  and  the  fibula,  then  between  the 
peroneus  longus  and  the  extensor  longus  digitorum,  leaving  fila- 
ments to  these  several  muscles  as  it  goes  along.  It  descends,  at 
the  outer  edge  of  the  last  muscle,  to  the  inferior  third  of  the  leg, 
giving  out,  in  the  mean  time,  many  muscular  branches.  Here  it 
penetrates  the  aponeurosis,  and  divides  into  cutaneous  branches, 
which  supply  the  lower  part  of  the  leg,  and  the  upper  surface  of  the 
foot  and  toes.  This  nerve  is  called,  by  the  French,  the  Musculo- 
Cutaneous  of  the  leg. 


Anat.  Atlas,  Fig.  631 . 


542 


NERVOUS  SYSTEM. 


The  Anterior  Tibial  Nerve  ( Tibialis  Anterior ) gets  obliquely  be- 
tween the  fibula,  the  peroneus  longus,  and  the  extensor  longus  digi- 
torum,  to  the  front  of  the  interosseous  ligament,  where  it  accompanies 
tire  anterior  tibial  artery.  It  passes,  with  the  artery,  under  the 
annular  ligament  of  the  ankle,  and  has  its  terminating  filaments 
going  to  the  muscles  and  integuments  of  the  upper  surface  of  the 
foot,  as  far  as  the  end  of  the  first  two  toes.  One  of  its  branches 
sinks  down  with  the  anterior  tibial  artery  to  the  sole  of  the  foot. 
High  up  in  the  leg  it  sends  filaments  to  the  knee-joint,  and,  in  its 
course  downwards,  it  furnishes  the  muscles  on  the  front  of  the  leg. 

The  Posterior  Tibial,  or  Popliteal  Nerve,*  ( Nervus  Popliteus ,) 
having  the  direction  mentioned,  is  placed  between  the  skin  and  the 
popliteal  vein.  It  gets  between  the  heads  of  the  gastrocnemius 
muscle,  and  perforates  the  origin  of  the  soleus ; going  with  the  pos- 
terior tibial  artery,  between  ibis  muscle  and  the  flexor  longus  digi- 
torum,  to  the  bottom  of  the  leg.  It  gives  off  the  following  branches: 

a.  The  External  Saphenus,  ( Saphenus  Externus , or  Communicans 
Tibice,)  which  arises  above  the  knee  joint,  and  descending  between 
the  skin  and  the  gastrocnemius,  turns  outwardly,  and  anastomoses 
with  the  cutaneous  branch,  alluded  to,  of  the  peroneal  nerve.  The 
common  trunk,  thus  formed,  passes  behind  the  external  ankle,  along 
the  external  margin  of  the  foot,  and  terminates  on  the  outer  toes; 
having  given  off  a great  number  of  cutaneous  branches. 

b.  Branches  to  the  heads  of  the  gastrocnemius,  soleus,  plantaris, 
and  popliteus. 

c.  Branches  to  the  flexor  longus  digitorum,  tibialis  posticus,  and 
to  the  flexor  longus  pollicis  pedis. 

d.  A branch  through  the  interosseous  ligament,  above,  to  the 
tibialis  anticus. 

e.  At  the  inferior  part  of  the  leg  many  cutaneous  filaments,  one  of 
which  gets  to  the  sole  of  the  foot. 

The  Posterior  Tibial  Nerve,  having  given  off  these  branches, 
divides,  in  the  hollow  of  the  os  calcis,  into  the  Internal  and  the 
External  Plantar  Nerve. 

The  Internal  Plantar  ( Plantaris  Internus)  proceeds  along-side  of 
the  tendon  of  the  flexor  longus  muscle  of  the  great  toe,  andthe  flexor 


Anat.  Atlas,  Figs.  632,  633,  634. 


NERVES  OF  LOWER  EXTREMITY. 


543 


longus  digitorum,  and  gives  filaments  to  the  contiguous  muscles.  It 
then  divides  in  such  a way  as  to  furnish  the  two  sides  of  the  first 
three  toes  and  the  internal  side  of  the  fourth. 

The  External  Plantar  ( Plantaris  Externus ) proceeds  with  the 
artery  of  the  same  name  to  the  outer  edge  of  the  foot,  between  the 
flexor  brevis  digitorum  and  the  flexor  accessorius.  It  is  distributed 
to  the  two  sides  of  the  little  toe,  and  to  the  external  side  of  the  fourth 
toe.  • One  branch  penetrates  to  the  interosseous  muscles  and  to  the 
transversalis  pedis.  A branch  of  considerable  size  is  also  detached, 
near  the  heel,  to  the  muscles  and  integuments  connected  with  the  os 
calcis. 


• - 


INDEX  TO  YOL.  II 


Abdomen  generally,  12 

General  situation  of  the  Visce- 
ra of,  15 
Regions  of,  14 
Veins  of,  296 

Abdominal  Aorta,  Branches  of,  256 
Absorbent  System,  Special  Anatomy  of, 
321 

General  Anatomy  of, 
312 

Absorbent  glands  of  the  Abdomen,  333 
Head  and  Neck, 
322 

Lower  extremi- 
ty, 326 

Parietes  of  the 
Trunk,  337 
Thorax,  339 
Upper  Extremi- 
ty, 324 

Absorbents  of  the  Pelvis,  327 

Head  and  Neck,  321 
Upper  Extremities,  and 
the  Contiguous  Parts 
of  the  Trunk  of  the 
Body,  323 

Inferior  Extremities, 
and  the  Contiguous 
Parts  of  the  Trunk  of 
the  Body,  323 
Organs  of  Digestion, 
329 

Parietes  of  the  Trunk, 
337 

Viscera  of  the  Thorax, 
334 

Accelerator  Urinre,  123 
Antrum  Pylori,  32 

Aorta,  and  the  Branches  from  its  Curva- 
ture, 231 

Aqueous  Humour,  465 
Aqueducts  of  Ear,  482 
Arachnoidea,  375 
Areola,  148 
Arcus  Sublimis,  253 
Arteries,  231 
Arteries,  Texture  of,  196 

Vol.  II.— 47 


Arteria  Aorta  Thoracica,  Branches  of,  254 
ad  Cutem  Abdominis,  271 
Alveolaris  Superior,  241 
Annstomotica,  (Arm,)  250 
Anastomotica,  (Thigh,)  274 
Articularis  Superior  Internal 

275 

Articularis  Superior  Externa,  275 
Articularis  Media,  275 
Articularis  Interior  Externa, 

275 

Articularis  Inferior  Interna,  275 
Aurieularis  Posterior,  239 
Axillaris,  246 
B isilaris,  414, 

Brachi  ilis,  249 
Bronchiales,  254 
Buccalis,  241 
Callosa,  412 
Capsulares,  261 
Carotis  Primitiva,233 
Carotis  Interna,  234 
Carotis  Externa,  234 
Cavernosa  Profunda  Penis,  269 
Coeliaca,  257 
Cerebri  Posterior,  414 
Cervicalis  Posterior,  245 
Choroidea,  412 
Ciliaris,  440 

Circumflexa  Anterior  of  Axillaris, 
248 

Circumflexa  Posterior,  248 
Circumflexa  Externa,  Profunda 
Femoris,  272 
Circumflexa  Interna,  272 
Circumflexa  Ilii,  270 
Colica  Sinistra  Superior,  260 
Colica  Sinistra  Media,  260 
Colica  Sinistra  Inferior,  261 
Communicans  Posterior  of  Brain, 
412 

Cystica,  258 
Colica  Dextra,  259 
Dentalis  Inferior,  241 
Dorsalis  Carpi,  251 
Dorsalis  Hallucis,  278 
Dorsalis  Manus,  253 


546 


INDEX. 


Arteria  Emulgentes,  261 
Epigastrica,  270 
Facialis,  236 
Femoralis,  271 
Frontalis,  442 
Gastrocnemia,  276 
Gastric®  Breves,  258 
Gasirica,257 
Gastica  Dextra,257 
Gastrica  Sinistra,  258 
Gemell®,  276 
Glutea,  267 

Hsemorrlioidea  Inferior  Externa, 
268 

Hremorrhoidea  Media,  266  » 
Hremorrhoidea  Superior  Interna, 
261 

Hepatica,  257 
Heliciua,  108 
Ileo  Colica,  259 
Iliac®  Primitiv®,  263 
Iliaca  Interna,  264 
Iliaca  Externa,  269 
Ilio-Lumb  iris,  264 
Innominata,  232 

Intercostales  Inferiures  AorticEe, 
255 

Iritercostalis  Superior,  244 
Interossea  Anterior,  253 
Interossea  Postei  ior,  253 
Infra-Orbitalis,  242 
Inferior  Cerebelli,  414 
Iscbiadica,  267 
Lachrymalis,  440 
Lingual  is,  236 
Lumbares,  262 
Magna  Pollicis,  251 
Mammaria  Externa,  247 
Mammaria  Interna,  244 
Maxillaris  Interna,  240 
Malleolaris  Externa,  277 
Malleolaris  Internn,277 
Mediastinales  Postcriores,  255 
Mesenlerica  Inferior,  260 
Mesenterica  Superior,  259 
Metatarsea,  278 
Meningea  Parva,  240 
Meningea  Magna,  240 
Mu-cularis  of  Orbit,  441 
Nutritia,  Brachialis,  249 
Nasalis,  442 
Obturatoria,  265 
Occipitalis,  238 
CEsophage®,  255 
CEthinoidea,  44 1 

Pancreatic®  Mediae  ct  Sinistra, 
258 

Pancreatico  Duodenalis,  258 
Media,  259 

Falatina  Superior,  242 
Palmaris  Profunda,  251 
Palpebralis,  441 
Peronea,  279 


Arteria  Pedicea,  278 
Perinea,  268 
Pterygoidea,  241 
Phrenic®,  256 
Pharyngea  Inferior,  237 
Plnryngca  Superior,  242 
Plan'aris  Externa,  280 
Plantaris  Interna,  280 
Poplitea,  274 
Profund  i Femoris,  272 
Prufunda  Major  Humeri,  249 
Profunda  Minor,  249 
Profundae  Perforantes  Femoris 
273 

Pudendte  Extern®,  272 
Pudica  Interna,  268 
P\  lorica,  258 
Radiabs,  250 
Radialis  Indicis,  251 
Recurrens  Radialis,  251 
Recurrens  Ulnaris,  252 
Sacra  Laterales,  265 
Spermatic®,  262 
Spinalis  Posterior,  414 
“ Anterior,  414 
Sacra  Media,  263 
Scapularis,  248 
Spheno-Palatina,  243 
Superior  Scapul®,  246 
Superficialis  Vol®,  261 
Superior  Ccri  b Hi,  414 
Subclaviana,  263 
Splenica,  258 
Tarsea,  277 
Temporalis,  239 
Thyroidea  Inferior,  244 
Thyroidea  Superior,  235 
Tboractca  Longa,  247 
Thoracica  Acromalis,  247 
Thoracica  Axillaris,  247 
Transversalis  Faciei,  239 
Temporalis  Media,  239 
Temporalis  Profunda,  241 
Thoracica  Superior,  247 
Tibialis  Anterior,  276 
Tibialis  Po-tica,  278 
Tibialis  Recurrens,  277 
Tympaniea,  240 
Ulnaris,  252 
Uterina,  266 
Umbilic®,  308 
Vertebralis,  243,413 
Vesicales,  266 
Arytenoid  Cartilages,  153 
Aryteno-Epiglottideus,  157 
Arytenoideus  Obliquus,  156 

Transversus,  157 
Arytenoid  Glands,  157 
Assimilation,  organs  of,  5 
Auditory  Nerve,  484 
Axillary  Artery,  Branches  of,  240 

Bellini  Ducts  of,  93 


INDEX. 


547 


Biliary  Ducts,  79 
Bile,  80 
Bladder,  99 

Structure  of,  100 
Bas-fond  of,  102 
Blood,  205 

Analysis  of,  216 

Coagulating  Lymph  of,  or  Fibrin, 
211 

Red  Globules  of,  213 
Serum  of,  209 
Bones  of  Tympanum,  475 
Brachial  Artery,  Branches  of,  249 
Broad  Ligaments  of  the  Uterus,  137 
Brunner,  Glands  of,  35 
Brain,  368 

Membranes  of,  369 
Veins  of,  415 

Carotids,  Branches  of,  234 
Capsule  of  Glisson,  21 
Caruncula  Myrtiformis,  134 
Cardiac  Orifice,  31 
Capillaries,  188 
Caul,  Situation  of,  16 
Coecum,  47 
Cerebellum,  384 
Cerebrum,  387 
Chambers  of  Eye,  466 
Choroidea,  448 
Chorda  Tympani,  485 
Chylopoietic  Viscera,  31 

Viscera  assistant,  67 

Cilia,  429 

Circulation  of  the  Foetus,  Peculiarities  of, 
303 

Circulation  of  the  Foetus,  Peculiarities  of, 
connected  with  its  Nourishment,  307 
Coccygeus  Muscle,  125 
Compressor  Urethrae,  104 
Conus  Vasculosus,  119 
Circulatory  System,  181 

Histology  of,  181 
Considerations  on, 
181 

Special  Anatomy  of, 
219 

Clitoris,  129 
Cochlea,  480 
Colon,  48 

Cummissura  Anterior,  401 
Conjunctiva,  430 
Corona  Glandis,  106 
Cornea,  446 
Corpus,  Callosum,  393 

Cavernosum,  107 
Ciliare,  449 
Dentatum,  386 
Fimbriatum,  140 
Highmorianum,  117 
Spongiosum,  108 
Spongiosum  Vaginae,  133 


Corpora  Albicantia.  390 
Striata,  392 
Crura  Cerebri,  389 
Couper’s  Glands,  114- 
Coronary  Arteries,  228,  229 
Veins,  229 

Corpora  Wolffiana,  98 
Cremaster  Muscle,  120 
Cricoid  Cartilage,  152 
Crico-Arytenoideus  Posticus,  156 
Lateralis,  156 
Crico-Thyroideus,  156 

Dartos  Muscle,  115 
Ductus  Ejaculatorius,  112 
Choledoch  us,  79 
Ducts  of  Bellini,  93 
Ferrein,  94 

Ductus  Galactophori,  146 
Dura  Mater,  369 
Ductus  Venosus,  307 

Arteriosus,  225,  306 
Duct  of  Liver,  72 
Ductus  Lactiferi,  146 
Duodenum,  41 
Dura  Mater,  Sinuses  of,  372 
Ductus  Wirsungii,  87 

Ear,  467 

Eminent  ice  Mammillares,  390 
Olivares,  380 
Endocardium,  227 
Epididymis,  119 
Epiglottis,  153 
Erector  Clitoridis,  130 
Penis,  123 

Eustachian  Valve,  305,  222 
Tube,  474 

External  Iliac  Artery,  Branches  of,  269 
Eye,  427 
Eyeball,  444 
Eyelids,  428 

Fallopian  Tubes,  139 
Foetus,  Peculiarities  of,  arising  from 
want  of  Respiration,  303 
Foetus,  Peculiarities  of  Circulation  con- 
nected with  its  nourishment,  307 
Follicles  of  Lieberkuhn,  57 
Fornix.  394 

Fossa  Navicularis,  110,  132 
Ovalis,  222 
Fourchette,  129 
Fourth  Ventricle,  402 
Frasnum  Penis,  106 
Frontal  Nerve,  491 

Fundamental  Portion  of  Cerebellum,  386 

Ganglion  Cavernous,  511 
Cervical,  512 
Lumbar,  520 
Lenticular,  488 
Spheno-Palatine,  426 


548  INDEX. 


Ganglion  Submaxillary,  498 
of  Laumonier,  5]  1 
Ribes,  511 
Sacral,  521 
Thoracic,  51 G 
Gall  Bladder,  77 
Glands,  5 

Glandules  Odoriferas  Tysonii,  106 
Pacchioni,  373 
Palpebrarum,  431 
Glandula  Pituitaria,  390 
Pinealis,  396 
Globus  Major,  119 
Minor,  119 

Glands  of  Brunner,  41 
Pever-,  41 

Gubcrnaculum  Testis,  121 

Head  and  Neels,  Veins  of,  282 
Heart,  219 

Right  Auricle  of,  221 
Right  Ventricle  of,  223 
Left  Auricle  of,  225 
Left  Ventricle  of,  225 
Blood  Vessels  of,  228 
Texture  of,  227 
Hymen,  134 

lleo-Colic  Valve,  47 
Ileum,  431 
Infundibulum,  390 
Incus,  476 

Internal  Iliac  Artery,  Branches  of,  264 
Inguinal  Glands,  326 
Intestinal  Canal,  37 
Intestine,  Small,  37 
Large,  44 

Small,  Situation  of,  15 
Large,  Situation  of,  15 

Iris,  453 

Isthmus  of  Vieussens,  222 

Jejunum,  43 

Kidneys,  91 

Situation  of,  16 
Minute  Structure  of,  92 

Labia,  Externa,  129 
Interna,  130 
Labyrinth,  478 
Lachrymal  Apparatus,  435 
Caruncle,  432 
Ducts,  436 
Gland,  435 
Nerve,  491 
Sac,  437 
Larynx,  151 
Lateral  Ventricles,  398 
Lactiferous  Glands,  144 
Levator  Ani,  125 
Lens,  462 
Lieberkuhn,  39.  52 


Ligamentum  Ciliare,  449 

Denticulatum,  366 
Palpebrale  Internum,  428 
Externum,  429 

Ligamentum  Suspensorium,  106 
Liver,  67 

Organization  of,  70 
Situation  of,  15 

Lower  Extremity,  Veins  of,  294 
Lobulus  Spigelii,  69 
Lungs,  169 

Texture  of,  170 
Lymphatic  Glands,  318 

Malleus,  475 

Malpighi,  Pyramid-'  of,  93 
Corpora  of,  92 
Mammae,  144 
Mesocolon,  44 
Meatus  Externus,  469 
Mediastinum  Anterior,  177 
Posterior,  177 
Superior,  178 
Medulla  Spinalis,  357 
Oblongata,  379 
Spinalis,  Nerves  of,  364 
Membrana  Pupillaris,  466 
Tympani,  472 

Membranous  Labyrinth,  481 
Mesentery,  43 
Mitral  Valve,  226 
Mons  Veneris,  129 
Morsus  Diaboli,  140 
Mucous  Coat,  Minute  Anatomy  of,  51 
Mucous  Glands,  and  Apparatus,  111 
Membranes,  Histology  of,  61 
Muscles  and  Fascia  of  Perineum,  122 
Musculus  Anterior  Auricute,  472 
Accelerator  Urinse,  123 
Attollens  Auricute,  471 
Antitragicus,  471 
Erector  Penis,  123 
Helicis  Major,  471 
Helicis  Minor,  471 
Laxator  Tympani,  477 
Levator  Palpebne  Superioris, 
433 

Obliquus  Oruli  Superior,  434 
Obliquus  Oculi  Inferior,  435 
Rectus  Oculi  Superior,  433 
Rectus  Oculi  Inferior,  434 
Rectus  Oculi  Externus,  433 
Rectus  Oculi  Internus,  434 
Retrahens  Auricute,  472 
Stapedius,  477 
Tensor  Tarsi,  438 
Tensor  Tympani,  477 
Tragicus,  471 
Transversus  Auricute,  471 

Nasal  Nerve,  490 
Neurine,  343 

Nervous  System,  Ehrenberg  on,  351 


INDEX. 


549 


Nervous  System,  343 

Special  Anatomy  of,  357 
Histology  of,  343 
Chemical  Analysis  of,  346 

Nerves  of  Encephalon,  402 
Ear,  484 

Nervus  Abdomino  Cruralis,  536 
Abdomino  Spinalis,  535 
Accessorius,  503 
Auditorius,  408 
Auricularis,  524 
Auricularis  Post.,  409 
Axillaris,  528 
Buccalis,  496 
Cardiacus  Medius,  514  • 
Cervicalis,  523 
Circumflexus,  528 
Cruralis  Anterior,  538 
Cutaneus  Externus,  529 
Cutaneus  Internus,  528 
Cutaneus  Femoris  Externus,  537 
Cutaneus  Femoris  Medius,  537 
Cutaneus  Femoris  Internus,  539 
Cutaneus  Femoris  Anterior,  538 
Cutaneus  Femoris  Posterior,  540 
Dentalis  Inferior,  497 
Descendens  Noni,  501 
Facialis,  499 
Frontalis,  491 
Glosso  Pharyngeus,  503 
Glutei,  539 
Hypoglossus,  501 
Infra  Maxillaris,  495 
Infra  Orbitalis,  492 
Ischiadicus,  540 
Laryngeus  Inferior,  507 
Laryngeus  Superior,  506 
Lingualis,  498 
Massetericus,  496 
Maxillaris  Superior,  491 
Medianus,  531 
Motor  Externus,  407 
Motor  Oculi,  405 
Nasalis  Internus,  425 
Naso-Palatinus,  426 
Obturatorius,  539 
Olfaclorius,  403 
Ophthalmicus,  489 
Opticus,  405 
Patheticus,  405 
Palatinus,  495 
Peroneus,  541 
Peroneus  Ext.,  541 
Petrosus  Superficialis,  494 
Petrosus  Profundus,  494 
Pharyugeus  Superior,  506 
Phrenicus,  526 
Plantaris  Externus,  543 
Plantaris  Internus,  542 
Pneumogastricus,  505 
Portio  Dura,  499 
Portio  Mollis,  408.  484 
Popliteus,  542 


Nervus  Pudendalis  Superior,  540 
Pudendalis  Inferior,  540 
Pterygo-Palatinus,  493 
Radialis,  530 
Renalis  Post.,  517 
Scapularis,  527 
Saphenus  Externus,  542 
Spermaticus  Externus,  537 
Splanehnicus,  516 
Spiralis,  530 
Snbcostales,  533 
Subcutaneus  Mai®,  492 
Suboccipitalis,  522 
Subscaimlaris,  527 
Sympatheticus,  510 
Trigeminus,  489 
Thoracicus,  528 
Tibialis  Anterior,  542 
Trochlearis,  488 
Ulnaris,  531 
Vidianus,  494 
Neurilemma  of  Nerves,  347 
Nose,  417 

Blood  vessels  of,  427 
Nerves  of,  423 
Nisus  Formativus,  195 

Omenta,  20 
Omentum  Colicum,  22 
Omentum  Gastro  Splenicum,  22 

Majus,  or  Gastro  Colicum, 

21 

Minus,  or  Hepatico  Gastricum, 

20 

Optic  Nerve,  404 
Orbit  Arteries  of,  440 
Nerves  of,  440 
Veins  of,  442 
Orbicular  Bone,  476 
Organs  of  Assimilation,  5 
Generation,  105 
Generation  in  the  Male,  105 
Generation  in  the  Female,  128 
Respiration,  151 
Os  Tine®,  136 
O'tium  Venosum,  223,  226 
Ovaries,  140 
Ovula  Graafiana,  141 

Pancreas,  86 

Situation  of,  16 
Minute  Structure  of,  86 
Papilla  Mainm®,  149 
Pa  pill®  Renales,  93 
Pelvic  Fascia,  127 
Penis,  105 
Pericardium,  220 
Perineal  Fascia,  122 
Perineum,  Muscles  and  Fascia  of,  122 
Peritoneum,  18 
Pia  Mater,  377 

Pigmentum  Nigrum  of  Eye,  450 
Pituitary  Gland,  390 


550 


INDEX. 


Plexus  Brachial  is,  526 
Cardiacus,  515 
Choroides,  399 
Coeliacus,  518 
Coronarius,  51S 
Cruralis,  536 
Diaphragmaticus,  518 
Gangliformis,  489,  511 
Hepaticus,518 

Htemorrhoidalis,  (Veins,)  296 
Ischiadicus,  539 
Lumbalis,  536 
Mesentericus  Inferior,  519 
Mesentericus  Superior,  519 
Pulmon.,  Ant.  508 
Post,  509 
Pudendalis,  297 
Retiformis,  133 
Renalis,  519 
Solaris,  517 
Sacralis,  (Veins,)  297 
Splenicus,  519 
Thoracicus,  516 
Uterinus,  297 
Vaginalis,  297 
Vesicalis,  (Veins,)  296 
Pituitary  Membrane,  420 
Pleura,  175 
Pineal  Gland,  396 
Plica  Semilunaris,  432 
Pori  Biliarii,  72 
Pons  Tarini,  390 
Prepuce,  106 

Primitive  Iliac  Artery,  Branches  of,  263 
Processus  Ciliaris,  451 
Prostate  Gland,  112 
Protuberantia  Annularis,  383 
Pulmonary  Artery,  224 
Pylorus,  32 

Rectum,  48 
Renal  Capsules,  89 

Minute  Structure  of,  90 
Situation  of,  16 

Retina,  456 

Rele  Vasculosum,  119 

Rima  Glottidis,  159 

Round  Ligaments  of  the  Uterus,  137 

Sacculus  Ellipticus,  481 
Sphericus,  481 
Sclerotica,  444 
Scrotum,  115 
Semicircular  Canals,  481 
Semilunar  Valves,  227 
Seminal  Vesicles,  111 
Senses,  417 

Serous  Membranes,  generally,  18 

Histology  of,  25 
Septum  Lucidum,  396 
Sinuses  of  Valsalva,  227 

the  Vertebral  Column,  290 
the  Dura  Mater,  372 


Sinus  Cavernosus,  374 
Circularis,  374 
Lateralis,  373 

Longitudinalis,  inferior,  373 
Lonvitudinalis,  superior,  3721 
Petrosi,  374 
Pulmonalis,  225 
Quartus,  373 

Soemmering’s  Foramen,  457 
Smegma  Prceputii,  106 
Spermatic  Chord,  120 
Sphincter  Ani,  124 

Vagina;,  133 
Vesicas,  102 
Spinal  Marrow,  360 

Membranes  of,  357 
Nerves  of,  364 
Vessels  of,  367 

Spleen,  80 

Situal  ion  of,  1 5 
Intimate  Structure  of,  81 
Stapes,  476 
Stomach,  31 

Situation  of,  15 

Subclavian  Artery,  Branches  of,  243 

Tarsi,  429 
Trenia  Striata,  393 
Tela  Choroidea,  400 
Testicles,  114 

Minute  Structure  of,  118 
Thalami  Optici,  391 
Third  Ventricle,  401 
Thymus  Gland,  167 
Thyreo-Arytenoid  Ligaments,  155 
Muscle,  156 
Epiglottideus,  157 
Hyoideus,  156 
Thyroid  Gland,  165 

Cartilage,  152 

Thoracic  Aorta,  Descending  Branches  of, 
254 

Ducts,  340 

Torcular  Hierophili,  373 
Trachea,  161 

Transversus  Perinei,  (Male,')  124 

(Female,)  133 

Tricuspid  Valve,  224 
Triangular  Ligament  of  the  Urethra,  126 
Tubuli  Seminiferi,  118 
Tuber  Cinereum,  390 
Tubercula  Quadrigemina,  391 
Tunica  Albuginea,  117 
Aracbnoidea,  375 
Hyaloidea,  461 
Vaginalis,  116 
Vasculosa,  118 
Tympanum,  472 
Tuberculum  Loweri,  222 

Umbilical  Artery,  308 
Vein,  307 

Upper  Extremity,  Nerves  of,  511 


INDEX, 


551 


Upper  ExtremityVeins  291 
Ureter,  97 

Urethra,  (Male,)  109 
(Female,)  131 
Urinary  Organs,  89 
Uterus,  and  its  Appendages,  134 
Uvula  Vesical,  101 

Vagina,  132 
Valve  of  Vieussens,  386 
Valvulae  Conniventes,  38 
Valvula  Thebesii,  223 
Vasa  Arteriarum,  200 
Capillaria,  188 
Efferentia,  119 
Recta,  1 1 8 
Vorticosa,  452 
Vasculum  Aberrans,  120 
Vas  Deferens,  120 
Veins  of  Abdomen,  296 

Head  and  Neck,  282 
Upper  Extremities,  291 
Lower  Extremities,  294 
Veins,  Texture  of,  202 
Vena  Azygos,  288 
Axillaris,  293 
Basilica,  292 
Cava  Inferior,  298 
Cava  Superior,  287 
Cephalica,  291 
Choroidea,  452 
Facialis,  282 
Femoralis,  294 
Galeni,  374 
Hypogastrica,  296 
Hemiazygos,  589 
Iliaca  Externa,  296 
Iliaca  Interna,  296 
Iliaca  Primiliva,  298 
Innominata,  287 
Intercostalis  Superior,  288 
Jugularis  Externa,  285 
Jugularis  Interna,  286 
Lingualis,  283 
Mammaria  Interna,  288 
Maxillaris  Interna,  285 


Vena  Mediana,  292 

Meseraica  Inferior,  301 
Superior,  301 
Occipital,  284 
Ophlhalmica,  443 
Palatina  Inferior,  283 
Pharyngea,  283 
Poplitea,  294 
Portarum,  73.  300 
Ranina,  283 
Sacra  Media,  298 
Saphena  Minor  Externa,  295 
Saphena  Magna  Interna,  295 
Splenica,  301 
Subclavia,  293 
Submentalis,  283 
Temporalis,  284 
Temporalis  Superficialis,  284 
Thyroidea  Inferior,  287 
Thyroidea  Superior,  283 
Vertebralis,  288 
Vcriae  Capsulares,  300 
Diploic®,  284 
Dorsales  Penis,  296 
Emulgentes,  300 
Hepatic®,  300 
Lumbales,  298 
Phrenic®  Inferiores,  300 
Spermatic®,  299 
Ventricles  of  the  Brain,  398 
Ventricle  of  Galen  or  Morgagni,  158 
Verumontanum,  109 
Vesical  Triangle,  101 
Vesicul®  Seminales,  111 
Vestibulum  ofVulva,  131 
Velum  Interpositum,  400 
Vesicle  ofPurkinje,  143 
Vestibulum  of  Ear,  478 
Villi,  39 

Vitreous  Humour,  460 
Vulva,  128 

Willis,  Circle  of,  415 
Winslow,  foramen  of,  22 
Wirsungius,  Duct  of,  87 
Wol. liana  Corpora,  98 


3 


JEFFERSON  MEDICAL  COLLEGE. 

SESSION  OF  1846—7. 

The  regular  Course  of  Lectures  will  commence  on  Monday  the  2d  day  of  November,  and 
end  on  the  last  day  of  February. 

Robley  Dunglison,  M.  D.,  Professor  of  Institutes  of  Medicine. 

Robert  M.  Huston,  M.  D.,  Professor  of  Materia  Medica  and  General  Therapeutics. 

Joseph  Panooast,  M.  D , Professor  of  General,  Descriptive  and  Surgical  Anatomy. 

John  K.  Mitchell,  M.D.,  Professor  of  Practice  of  Medicine. 

Thomas  D.  Mutter,  M.  D.,  Professor  of  Institutes  and  Practice  of  Surgery. 

Charles  D.  Meigs,  M.  D.,  Professor  of  Obstetrics  and  Diseases  of  Women  and  Children. 

Franklin  Bache,  M.  D.,  Professor  of  Chemistry. 

Every  Wednesday  and  Saturday  during  the  course,  Medical  and  Surgical  cases  are  investigated  and  pre- 
scribed for  before  the  class  During  the  past  year  not  fewer  than  1,000  cases  were  treated,  and  upwards  of  172 
were  operated  on.  The  Clinical  Lectures  are  so  arranged  as  to  permit  the  student,  should  he  desire  it,  to  attend 
the  Medical  and  Surgical  practice  and  lectures  at  the  Pennsylvania  Hospital. 

On  and  after  the  1st  of  October,  the  dissecting  rooms  of  the  College  will  be  open  under  the  direction  of  the 
Professor  of  Anatomy  and  the  Demonstrator. 

Owing  to  the  large  size  of  the  class,  which  numbered  469  during  the  last  session,  it  became  expedient  to 
make  extensive  and  important  alterations  in  the  college  edifice.  These  will  be  completed  by  the  1st  of  Sep- 
tember. 

R.  M.  HUSTON,  M.  D.,  Dean  of  the  Faculty. 

No.  1 Girard  Street. 

GEO.  W.  CARPENTER  & CO., 

WHOLESALE  ©RUGGISTS, 

Wo.  301  Market  Street. 

Have  always  on  hand  a large  and  general  assortment  of  choice  Drugs  and  Medicines,  Surgical  Instruments, 
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A UNIFORM  AND  CHEAP  EDITION  OF 

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m THREE  LARGE  VOLUMES. 

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OF 

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BLE COLUMNED  PAGES. 

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The  frequent  inquiries  for  a uniform,  compact  and  good  edition  of  Boz’s  works,  have  induced  the  publishers 
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primed  on  fine  white  paper,  with  good  type,  and  forms  three  large  volumes,  averaging  about  seven  hundred 
and  ;fifty  pages  each,  done  up  in  various  styles  of  extra  cloth,  making  a beautiful  and  portable  edition. — 
Some  of  the  works  are  illustrated  with  wood  engravings. 


Will  be  Ready  in  September  1846, 

A FOURTEENTH  AND  SUPPLEMENTARY  VOLUME  OF  THE 

ENCYCLOPEDIA  AMERICANA. 

BY  HENRY  YETRAKE,  Esq.,  LL.  D., 

One  of  the  Professors  in  the  University  of  Pennsylvania,  4-c.,  fyc. 

Thirteen  years  have  now  elapsed  since  the  publication  oS the  last  additions  to  the  Encyclopaedia  Americana, 
•and  the  numerous  important  events  which  have  transpired  since  then,  the  advance  made  in  all  the  sciences 
, and  arts,  and  the  number  of  distinguished  men  who  have  become  legitimate  subjects  for  biography,  render  a 
supplement  necessary  for  the  numerous  readers  of  this  widely  diffused  and  popular  work.  In  the  hands  of 
Professor  Vethake,  this  difficult  task  has  been  faithfully  executed,  and  in  a short  time,  those  who  possess  the 
^Encyclopaedia,  will  be  able  to  add  to  it  this  new  volume. 

Any  of  the  books  in  the  following  catalogue  can  be  furnished  by  G.  W.  Carpenter  4-  Co.,  or  other 
Druggists  of  Philadelphia  or  New  York. 


4 


MISCELLANEOUS  WORKS 

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PUBLISHED  BY  LEA  AND  BLANCHARD, 


Acton's  Modern  Cookery,  with  cuts,  12mo,  cloth. 

American  Ornithology,  by  Prince  Charles  Bonaparte, 
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Addison  on  Contracts,  at  press. 

Amott’s  Elements  of  Physics,  1 vol.  8vo,  sheep. 

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numerous  plates. 

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Browne’s  Religio  Medici,  l vol.  12mo,  extra  cloth. 

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the  same;  A Treatise  on  all  the  French  Verbs,  Regu- 
lar and  Irregular.  The  whole  forming  five  small 
volumes,  half  bound  to  match. 

Butler’s  Atlas  of  Ancient  Geography,  8vo,  half  bound. 

Butler’s  Geographia  Classica,  1 vol.  8vo. 

Brigham  on  Mental  Cultivation,  Ac.,  12rno,  cloth. 

Bridgewater  Treatises.  The  whole  complete  in  7 vols. 
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my ; Bell  on  the  Hand  ; Kidd  on  the  Physical  Condi- 
tion of  Man;  Buckland’s  Geology,  2 vols.,  with  nu- 
merous plates  and  maps. 

Roget,  Buckland,  and  Kirby  are  sold  separate. 

Brougham  on  the  French  Revolution,  1 vol.,  paper. 

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Barnaby  Rudge,  by  “ Boz,”  paper  or  cloth. 

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Clater’s  Cattle  and  Sheep  Doctor,  1 vol.  12mo,  cuts. 

Davidson,  Margaret,  Memoirs  of  and  Poems,  in  1 vol. 
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Davidson,  Mrs  , Poetry  and  Life,  in  1 vol.  12mo,  paper, 
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Dog  and  Sportsman,  by  Skinner,  plates,  1 v.  12mo,  c’th. 

Dunglison  on  Human  Health,  1 vol.  8vo. 

Encyclopaedia  of  Geography,  in  3 vols.  8vo,  many  cuts. 

Encyclopaedia  Americana,  13  vols.  8vo.  A supple- 
mentary vol.  (I4th^  is  nearly  ready. 

East’s  Reports,  edited  by  G.  M.  Wharton,  in  8 vols. 
large  8vo,  law  sheep. 

Education  of  Mothers,  1 vol.  12mo,  cloth  or  paper. 

Electro-Magnetic  Telegraph,  by  Vail,  8vo,  sewed. 

Frederic  the  Great,  2 vols  12mo,  extra  cloth. 

Fielding’s  Select  Works,  in  1 vol.  8vo,  cloth. 

Francatelli’s  Modern  French  Cook,  in  1 vol.  8vo,  with 
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cuts. 

Grahame’s  Colonial  History,  2 vols.  8vo,  a new  ed. 

Gieseler’s  Ecclesiastical  History,  3 vols.  8vo. 

Griffith’s  Chemistry  of  the  Four  Reasons,  1 v.  12mo,  cuts. 

Hawker  on  Shooting,  with  cuts,  preparing. 

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Hemans’  Complete  Poetical  Works,  in  7 vols.  12mo. 

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Hill  on  I 'rusiees,  1 large  vol.  8vo.  law  sheep. 

Ingersoll’s  History  of  the  Late  War,  1 vol.  8vo. 

Irving’s  Works,  2 vols.  super- royal  8vo. 

Irving's  Columbus,  in  2 vols.  8vo. 


Irving’s  Beauties,  in  1 vol.  18mo. 

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Jesse’s  Court  of  England,  in  3 vols.  12mo. 

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Kirby  and  Spence’s  Entomology,  1 large  8vo  vol.,  with 
plates,  plain  or  colored. 

Life  of  Thomas  Jefferson,  by  Judge  Tucker,  2 vols.  8vo. 
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Ranke’s  History  of  the  Reformation  in  Germany,  to  be 
complete  in  1 vol. 

Ranke’s  History  of  the  Ottoman  and  Spanish  Empires. 
Rogers’  Poems,  a splendid  edition,  illustrated,  imp.  8vo. 
Roget’s  Outlines  of  Physiology,  1 vol.  8vo. 

Roscoe’s  Lives  of  the  Kings  of  England,  a 12mo  series 
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Sportsman’s  Library,  by  Mills,  1 vol.  12mo. 

Select  Works  of  Tobias  Smollett,  cloth  or  paper. 
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Small  Books  on  Great  Subjects— containing  “Philo- 
sophical Theories  and  Philosophical  Experience” — 
“On  the  Connection  between  Physiology  and  Intel- 
lectual Science” — “ On  Man’s  Power  over  himself  to 
Prevent  or  Control  Insanity” — “An  Introduction  to 
Practical  Organic  Chemistry”  — “A  Brief  View  of 
Greek  Philosophy  up  to  the  Age  of  Pericles” — “A 
Brief  View  of  Greek  Philosophy  from  the  Age  of 
Socrates  to  the  Coming  of  Christ”— “ Christian  Doc- 
trine and  Praciice  in  the  Second  Century” — “An  Ex- 
position of  Vulgar  and  Common  Errors,  adapted  to 
the  Year  of  Grace  1845'’ — “An  Introduction  to  Vege- 
table Physiology  with  references  to  the  works  of  De 
Candolle,  Lindley,  Ac.” — “On  the  Principles  of  Cri- 
minal Law,” — “Christian  Sects  in  the  Nineteenth 
Century,”  Ac. — each  work  in  1 small  vol.,  price  25 
cents,  forming  a neat  and  cheap  series  “The  Con- 
nection between  Physiology  and  Intellectual  Sci- 
ence” and  “Principles  of  Criminal  Law”  are  now 
ready,  and  the  others  will  shortly  follow,  with  new 
works  now  preparing  for  the  series. 

Spence  oil  the  Jurisdiction  of  the  Court  of  Chancery, 
at  press 

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for  Schools,  Colleges,  Ac.,  with  Questions  by  Pro- 
fessor Hart,  in  1 vol.  large  12mo,  extra  cloth,  or  half 
bound. 

Wheaton’s  International  Law,  1 vol.  large  8vo,  law 
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Wheaton  on  the  Right  of  Search,  in  1 vol.  8vo. 

Mrs.  Washington  Potts,  by  Miss  Leslie,  25  c$nts. 
Wraxall’s  Posthumous  Memoirs,  1 vol.  8vo. 

W raxaJP.s  Historical  Memoirs.  1 vol.  Svo. 

Youatt  on  the  Horse,  Ac.,  1 vol.  Svo. 
j Youatt  on  the  Dog,  with  plates,  preparing. 


5 


TO  THE  MEDICAL  PROFESSION. 

The  following  list  presents  nearly  all  the  works  on  Medical  Science  published,  at  press  and 
preparing  by  the  Subscribers.  They  will  be  found  to  be  executed  in  a superior  style,  and  sold 
at  prices  as  low  as  can  be  afforded  consistent  with  correct  editions.  These  works  can  be  had 
in  all  the  principal  bookstores  throughout  the  Union;  from  which,  or  from  the  subscribers,  all  in- 
formation relative  to  prices,  &c.,  can  be  obtained,  on  application,  free  of  postage. 

LEA  BE  A JVC  SI  A M JJ9  Philadelphia. 


Anatomical  Atlas,  by  Smith  & Horner,  imp.  8vo,  650  figs. 
Arnott’s  Elements of  Physics,  new  ed.  1 vol.  Svo,  484  pp. 
American  Medical  Journal,  quarterly  at  S5  a year. 
Abercrombie  on  the  Stomach,  1 vol.  8vo,  320  pages. 
Abercrombie  on  the  Brain,  new  ed.,  1 vol.  Svo,  324  pp. 
Alison’s  Outlines  of  Pathology,  in  1 vol.  Svo,  420  pp. 
Ashwell  on  Females,  one  vol.  Svo,  520  pages. 

Andral  on  the  Blood,  120  pages,  Svo. 

Bird  oil  Urinary  Deposits,  1 vol.  Svo,  22S  pp. 

Bird’s  Natural  Philosophy,  preparing. 

Burrows  on  Cerebral  Circulation,  preparing. 

Budd  on  the  Liver,  1 vol.  8vo,  392  pp. 

Buckland’s  Geology  hnd  Mineralogy,  2 vols:  Svo,  with 
numerous  plates  and  maps. 

Berzelius  on  the  Kidneys  and  Urine,  1 vol.  Svo,  ISO  pp. 
Bridgewater  Treatises,  with  numerous  illustrations,  7 
vols.  Svo.  32S7  pp. 

Bartlett  on  Fevers,  &c..,  1 vol.  Svo.,  394  pages. 
Bartlett’s  Philosophy  of  Medicine,  1 vol.  Svo,  312  pp. 
Brigham  on  Mental  Excitement,  1 vol.  12mo.  204  pp. 
Billing’s  Principles  of  Medicine,  1 vol.  8vo,  304  pp. 
Brodie  on  Urinary  Organs,  1 vol.  Svo,  214  pp. 

Brodie  on  the  Joints,  1 vol.  Svo,  216  pp. 

Brodie’s  Surgical  Lectures,  1 vol.  Svo,  350  pp. 
Benedict’s  Compendium  of  Chapman’s  Lectures,  1 vol. 
8vo,  258  pp. 

Chapman  on  Viscera,  1 vol.  Svo,  384  pages. 

Chapman  on  Fevers,  Gout,  &c.,  1 vol.  Svo,  450  pp. 
Chelius’  Surgery,  by  South  and  Norris,  at  press. 
Chitty’s  Medical  Jurisprudence,  Svo,  510  pp. 

Clater  and  Skinner’s  Farrier.  12mo,  cloth,  220  pp. 
Carpenter’s  Principles  of  Human  Physiology,  1 vol. 

8vo,  644  pages,  with  cuts,  second  edition. 

Carpenter’s  General  and  Comparative  Physiology,  1 
vol.  8vo,  preparing,  many  plates. 

Carpenter’s  Vegetable  Physiology,  1 vol.  12mo,  with 
cuts,  300  pp. 

Carpenter’s  Manual,  or  Elements  of  Physiology,  1 vol. 
Svo,  566  pages,  many  cuts. 

Carpenter’s  Cyclopedia  of  Natural  Science,  preparing. 
Cooper,  Sir  Astley  on  Hernia,  imp.  Svo,  plates,  428  pp. 
Cooper  on  Dislocations,  1 vol.  Svo,  with  cuts,  500  pp. 
Cooper  on  the  Testis  and  Thymus  Gland,  1 vol.  impe- 
rial Svo,  many  plates. 

Cooper  on  the  Anatomy  and  Diseases  of  the  Breast,  &c. 

&c.,  1 vol.  imperial  8vo.  splendid  lithographic  plates. 
Condie  on  Diseases  of  Children,  1 vol.  Svo,  652  pages. 
Churchill  on  Females,  3d  edition,  1 vol.  Svo.  572  pp. 
Churchill’s  Midwifery,  1 vol.  Svo.  520  pp.,  many  cuts. 
Cyclopaedia  of  Practical  Medicine,  by  Forbes,  &c. 
Edited  by  Dunglison,  in  4 large  super-royal  vols., 
3154  double  columned  pages. 

Carson’s  Medical  Formulary,  in  preparation. 

Dewees’  Midwifery,  with  plates,  10th  edit.,  660  pp. 
Dewees  on  Children,  8th  edition,  548  pp. 

Dewees  on  Females,  with  plates,  8th  edition,  532  pp. 
Durlacher  on  Corns,  Bunions,  &c.,  1 vol.  12rno  . 134  pp. 
Dunglison’s  Physiology,  6th  edition,  2 vols.  8vo,  1350 
pages,  with  370  cuts. 

Dunglison’s  Therapeutics  and  Materia  Medica,  a new 
edition,  with  cuts.  2 vols.  8vo,  986  pages. 

Dnnglison’s  Medical  Dictionary,  6ih  edition,  1 vol.  Svo, 
804  very  large  pages,  double  columns 
Dunglison  on  New  Remedies,  4lh  edition,  616  pp. 
Dunglison  on'Human  Healih,  in  1 vol  8vo,  464  pp. 
Dunglison’s  Practice  of  Medicine,  2d  edition,  2 vols. 
8 vo,  1322  pp. 

Dunglison’s  Medical  Student,  1 vol.  12mo,  312  pp. 
Druitt’s  Surgery.  1 vol.  Svo,  5:34  pp.,  2d  ed.,  many  cuts. 
Ellis’  Medical  Formulary,  a new  edition,  nearly  ready. 
Elliotson’s  Mesmeric  Cases,  Svo,  56  pp. 

Esquirol  on  Insanity,  by  Hunt.  496  pp. 

Fownes’  Elementary  Chemistry,  l vol.  royal  12mo,  460 
pages,  many  cuts. 

Fevers.  General  and  Special,  edited  by  Clymer,  1 vol. 
Svo,  600  pages. 


Fergusson’s  Practical  Surgery,  1 vol.  Svo,  2d  ed  , 640 pp. 

Graham’s  Chemistry,  with  cuts,  1 vol.  Svo,  750  pp. 

Griffith’s  Chemistry  of  the  Four  Seasons,  1 voi.  12mo. 
with  cuts. 

Griffith’s  Medical  Botany,  many  illustrations,  at  press. 

Guthrie  on  the  Bladder  and  Urethra.  1 vol.  Svo,  150  pp. 

Hoblyn’s  Dictionary  of  Medical  Terms,  by  Hays,  1 vol. 
large  l2mo,  402  pages. 

Hams  on  the  Maxillary  Sinus,  1 vol.  Svo,  166  pages. 

Horner’s  Special  Anatomy,  2 vols.  Svo,  7th  ed.,  cuts. 

Horner’s  New  Dissector,!  vol.  12mo,  with  many  cuts. 

Hasse’s  Pathological  Anatomy,  nearly  ready. 

Hope  on  the  Heart.  1 vol  Svo,  with  plates,  a new  ed. 

Harrison  on  the  Nervous  System,  1 vol.  Svo,  292  pp. 

Hughes  on  the  Lungs  and  Heart,  1 vol.  12mo,  270  pp. 

Jones’  (T.  Wharton)  Manual  of  Ophthalmic  Surgery, 
with  many  cuts,  at  press. 

Jones  and  Todd  on  the  Ear,  1 vol. f preparing. 

Kirby  on  Animals,  many  plates,  1 vol.  Svo,  520  pp. 

Kirby  and  Spence’s  Entomology,  1 vol.  8vo,  600  pages, 
plates,  plain  or  colored. 

Lawrence  on  the  Eye,  a new  ed.,  many  cuts,  1 vol.  8vo. 

Lawrence  on  Ruptures.  1 vol.  8vo,  480  pp. 

Liston’s  Surgery',  by  Mutter,  1 vol.  8vo,  566  pp.,  many 
cuts. 

Miller’s  Principles  of  Surgery,  1 vol.  Svo,  526  pp. 

Miller’s  Practice  of  Surgery,  l vol.  Svo,  496  pp. 

Maury’s  Dental  Surgery,  with  plates.  1 vol.  8vo,  2S6pp 

Muller’s  Physiology,  1 vol.  8vo,  SS6  pages. 

Medical  News  and  Library,  published  monthly. 

Meigs’  Translation  of  Colombat  de  l’ls^re  on  the  Dis- 
eases of  Females,  1 vol.  8vo,  720  pp. 

Metcalf  on  Caloric,  in  one  large  vol.,  Svo,  (at  press.) 

Prout  on  the  Stomach,  1 vol.  Svo,  col’d  plates,  466  pp. 

Popular  Medicine,  by  Coates,  1 vol.  Svo.  614  pages. 

Philip  on  Protracted  Indigestion,  1 vol.,  240  pages. 

Phillips  on  Scrofula,  1 vol  Bvo,  350  pages. 

Pereira’s  Materia  Medica.  2 vols  Svo,  1580  very  large 
and  closely  printed  pages.  Second  Edition. 

Royle’s  Materia  Medica, "with  wood-cuts,  nearly  ready. 

Roget’s  Animal  and  Vegetable  Physiology,  with  many 
cuts.  2 vols.  8vo,  872  pages. 

Roget’s  Outlines  of  Physiology',  1 vol.  8vo.  516  pages. 

Rigby’s  System  of  Midwifery,  1 vol.  Svo  492  pages. 

Ricord  on  Venereal,  new  edition,  1 vol.  Svo  256  pages 

Ricord’s  large  work  on  Venereal  Diseases,  w’ith  nume- 
rous plates,  preparing 

Ramsbotham  on  Parturition,  with  many  plates,  1 vol 
imperial  bvo  a new  and  improved  edition.  520  pp. 

Robertson  on  the  Teeth,  1 vol.  Svo,  230  pages. 

Simon’s  Chemistry  of  Man,  1 vol.  bvo,  730 pages. 

Taylor’s  new  work  on  Medical  Jurisprudence,  by  Grif- 
fith, 1 vol.  Svo.  540  pages. 

Traill’s  Medical  Jurisprudence,  1 vol.  Svo,  234  pages. 

Trimmer’s  Geology  and  Mineralogy,  1 vol.  Svo.  528  pp. 

Todd  & Bowman's  Physiology',  publishing  in  the  Medi- 
cal News  and  Library,  many  cuts. 

Thomson  on  the  Sick  Room.  1 vol.  12mo,  360  pp.,  cuts. 

Vogel’s  Pathological  Anatomy,  with  plates,  preparing. 

Walshe  on  the  Diseases  of  the  Lungs,  1 vol.  12mo,  310 
pages. 

Watson’s  Principles  and  Practice  of  Physic,  by  Con- 
die, 1 vol.  Svo,  1060  large  pages. 

Wilson’s  Human  Anatomy',  wnth  cuts,  1 vol.  Svo,  a new 
and  improved  edition.  608  pages 

Wilson’s  Dissector  or  Practical  and  Surgical  Anato- 
my. by  Goddard,  with  cuts,  1 vol.  12mo,  444  pages. 

Wilson  on  the  Skin.  1 vol  Svo,  370  pages. 

Williams’  Pathology,  or  Principles  of  Medicine,  1 vol. 
Svo.  384  pages. 

Williams’  Lectures  on  the  Stomach,  &c..  preparing. 

Williams  on  the  Respiratory  Organs,  by  Clymer,  1 vol. 
Svo.  50o  pa^es. 

Youatt  on  the  Horse,  by  Skinner,  cuts,  448  pp.  1 vol.  8yo 

Youatt  and  Clater’s  Cattle  Doctor,  1 vol.  12mo,  with 
cuts,  282  pages 


***  They  have  other  works  in  preparation  not  included  in  this  list 


6 


LEA  & BLANCHARD’S  PUBLICATIONS. 


Now  Ready, 

CARPENTER’S  NEW  WORK. 


A MANUAL,  OR 

ELEMENTS  OF  PHYSIOLOGY, 

INCLUDING  PHYSIOLOGICAL  ANATOMY. 

FOR  THE  USE  OF  THE  MEDICAL  STUDENT. 

BY  WILLIAM  B.  CARPENTER,  M.  D.,  F.  R.  S„ 

Fullerian  Professor  of  Physiology  in  the  Royal  Institution  of  Great  Britain,  &c. 

With  One  Hundred  and  Eighty  Illustrations, 

IN  ONE  OCTAVO  VOLUME  OF  566  PAGES. 

Elegantly  printed  to  match  his  “ Principles  of  Human  Physiology.55 

The  sheets  of  this  volume,  in  their  passage  through  the  press  have  been  carefully  examined  by 
Dr.  Meredith  Clymer,  the  editor  of  Dr.  Carpenter’s  Principles  of  Physiology.  The  manner  in  which 
the  work  is  brought  up  to  the  day,  and  its  perfect  adaptation  to  its  purposes  as  an  elementary  text- 
book for  students  have  rendered  unnecessary  any  alterations  or  additions.  The  efforts  of  the  pub- 
lishers have  therefore  been  directed  to  obtaining  a correct  reprint  of  the  London  edition. 

‘•The  aumor  has  shown  singular  skill  in  preserving  so  marked  a line  of  distinction  between  the  present 
Manual  and  the  4 Principles  of  Physiology’  previously  published  by  him.  They  are  both  on  precisely  the  same 
subject;  but  the  one  is  neither  a copy,  nor  an  abstract,  nor  an  abridgment  of  the  other.  In  one  thing,  how- 
ever, they  are  exactly  alike— in  their  general  excellence,  and  in  their  perfect  adaptation  to  their  respective 
purposes.  The  reputation  of  Dr.  Carpenter  as  a physiologist  is  too  well  established  throughout  the  whole  medi- 
cal world  to  admit  of  increase  from  any  commendation  of  ours;  but  we  should  be  doing  injustice  to  our  own 
feelings  if  we  did  not  here  express  our  admiration  of  his  great  intellectual  powers,  of  his  extensive  learning, 
of  the  comprehensiveness  of  his  views,  of  the  quickness  with  which  he  seizesthe  important  points  and  bearings 
of  each  subject,  of  the  logical  order  in  which  he  arranges  his  facts,  and  of  the  clearness  and  precision  with 
•which  he  explains,  and  exposes  his  doctrines.  Ur.  Carpenter’s  various  treatises  are  in  fact  models  in  their 
respective  departments.  It  is  their  great  and  varied  excellence  which  accounts  for  their  unrivalled  popularity. 
We  can  pay  no  higher  compliment  to  the  work  before  us,  than  to  say,  that  it  is  equal  in  merit  to  the  former 
productions  of  the  author.  This  is  equivalent  to  say  mg  that  it  is,  without  question,  the  best  manual  or  short 
treatise  on  physiology  extant.  Although  designed  for  the  student,  and  framed  expressly  to  meet  his  wants ; it  is 
a work,  we  will  venture  to  say,  that  may  be  consulted  with  advantage  by  most  physicians  and  surgeons,  how- 
ever learned.” — The  British  and  Foreign  Medical  Review. 


CARPENTER’S  HUMAN  PHYSIOLOGY. 

PRINCIPLES  OF  HUMAN  PHYSIOLOGY. 

WITH  THEIR  CHIEF  APPLICATIONS  TO 

PATHOLOGY,  HYGIENE,  AND  FORENSIC  MEDICINE. 

BY  WILLIAM  B.  CARPENTER,  M.  D.,  F.R.S.,  &c. 

Second  American,  from  a Hew  and  Revised  London  Edition. 

WITH  NOTES  AND  ADDITIONS, 

BY  MEREDITH  CLYMER,  M.  D.,  &c. 

With  Two  Hundred  and  Sixteen  Wood-cut  and  other  Illustrations. 

In  one  octavo  volume,  of  about  650  closely  and  beautifully  printed  pages. 

The  very  rapid  sale  of  a large  impression  of  the  first  edition  is  an  evidence  of  the  merits  of  this  valuable  work 
and  that  it  has  been  duly  appreciated  by  the  profession  of  this  country.  The  publishers  hope  that  the  present 
edition  will  be  found  still  more  worthy  of  approbation,  not  only  from  the  additions  of  the  author  and  editor,  but 
also  from  its  superior  execution,  and  the  abundance  of  its  illustrations.  No  less  than  eighty-five  wood-cuts  and 
another  lithographic  plate  will  be  found  to  have  been  added,  atfording  the  most  material  assistance  to  the  student. 

We  have  much  satisfaction  in  declaring  our  opinion  that  this  work  is  the  best  systematic  treatise  on  physi- 
ology in  our  own  language,  and  the  best  adapted  for  the  student  existing  in  any  language.  Medico- Ckirurgi- 
cal  Review. 

“The  woik  as  it  now  stands  is  the  only  Treatise  on  Physiology  in  the  English  language  which  exhibits  a clear 
and  connected,  and  comprehensive  view  of  the  present  condition  of  that  science  London  and  Edinburgh 
Monthly  Journal. 

CARPENTER’S  POPULAR  TREATISE 
ON  VEGETABLE  PHYSIOLOGY. 

In  one  neat  duodecimo  volume,  extra  cloth,  with  numerous  illustrations. 

This  work  forms  a part  of  Carpenter’s  Popular  Cyclopedia  of  Natural  Science,  the  remainder  of 
which  will  be  published  with  all  the  beautiful  illustrations. 


CARPENTER’S  PRINCIPLES  OF  GENERAL  AND  COMPARATIVE 
PHYSIOLOGY,  AND  HIS  WORK  ON  ANIMAL  PHYSIOLOGY, 

WITU  ALL  THE  BEAUTIFUL  ILLUSTRATIONS,  ARE  NOW  PREPARING. 


LEA  & BLANCHARD’S  PUBLICATIONS. 


7 


LISTON  AND  MUTTER’S  SURGICAL  LECTURES. 

A BEAUTIFUL  VOLUME,  PROFUSELY  ILLUSTRATED. 

LECTURES  ON  THE  OPERATIONS  OF  SURGERY, 

AND  ON 

DISEASES  AND  ACCIDENTS  REQUIRING  OPERATIONS 

DELIVERED  AT  UNIVERSITY  COLLEGE,  LONDON, 

BY  ROBERT  LISTON,  ESQ.,  F.R.S.,  &c. 

EDITED,  WITH  NUMEROUS  ALTERATIONS  AND  ADDITIONS, 

BY  T.  D.  MUTTER,  M.D., 

PROFESSOR  OF  SURGERY  IN  THE  JEFFERSON  MEDICAL  COLLEGE,  PHILADELPHIA. 

IN  ONE  LARGE  AND  BEAUTIFULLY  PRINTED  OCTAVO  VOLUME. 

WITH  TWO  HUNDRED  AND  SIXTEEN  ILLUSTRATIONS  ON  WOOD. 

This  work  contains  much  original  matter  of  Professor  Mutter’s,  amounting  to 
about  two  hundred  and  fifty  pages,  embodying  the  results  of  his  great  experience, 
and  adapting  the  whole  to  the  wants  of  the  American  Profession.  The  Lectures 
are  those  which  have  attracted  so  much  attention  as  published  in  the  Lancet 
They  are  here  reproduced  entire,  omitting,  none  of  the  original  wood  engravings, 
and  introducing  many  new  and  valuable  ones,  rendering  this  altogether  one  of 
the  most  completely  illustrated  works  of  the  kind  that  has  for  some  time  been 
presented  to  the  medical  public.  Among  the  additions  of  Professor  Mutter  will 
be  found  full  and  elaborate  Treatises  on  Staphyloraphy,  the  different  Plastic  Ope- 
rations, Club-Foot,  Affections  of  the  Eye,  Deformities  from  Burns,  and  many 
other  important  subjects,  not  to  be  met  with  in  so  enlarged  a form  in,  perhaps, 
any  other  work  on  Surgery.  The  chapters  containing  them  are  fully  illustrated 
with  numerous  original  and  highly  curious  engravings. 

“This  is  a very  attractive  book,  both  in  respect  to  mechanical  execution  and  contents.  Printed  on  fine 
white  paper,  with  a fair  new  type,  and  embellished  with  more  than  200  well  executed  wood- cuts,  it  presents 
altogether  as  beautiful  an  appearance  as  a work  of  art  as  its  matter  is  interesting  and  important  to  the  prac- 
tical surgeon.  The  lecture  on  operations  on  the  eye  is  a very  lucid  and  instructive  one,  but  we  can  only  reter 
to  it  in  the  most  cursqry  manner.  The  editor  has  fully  supplied  everything  that  was  wanting  to  render  the 
chapter  complete,  and  we  would  gladly  quote  his  remarks  on  the  operations  of  Strabismus  and  Staphyloma, 
did  our  limits  permit.  The  chapter  on  Cataract,  by  Dr.  Mutter,  extending  over  thirty  pages,  we  look  upon  as 
one  of  the  most  valuable  essays  on  the  subject  in  the  language.  It  is  clear  and  methodical,  sufficiently  full,  yet 
precise,  and  abounding  in  practical  precepts  of  the  highest  interest.  The  remarks  on  deformities  of  the  nose 
are  evidently  the  result  of  much  experience  and  observation.  The  operations  for  hare-lip  and  cleft  palate  are 
treated  at  considerable  length,  and  made  exceedingly  clear  by  means  of  the  accompanying  illustrations:  we 
can  recommend  these  sections  alone  as  worth  far  more  to  the  surgeon  than  many  times  the  price  of  the  whole 
work.  The  same  remark  will  apply  to  the  next  lecture,  on  the  Diseases  of  the  Antrum,  Carious  Teeth,  Erected 
Tumours  of  the  Face,  and  Solid  and  Encysted  Tumors.  YVe  know  of  no  systematic  work  on  surgery  in  which 
the  anaplastic  operations  for  removal  or  remedying  deformities  of  the  face  are  so  fully  and  satisfactorily  de 
scribed  as  in  this.  But  we  have  already  exceeded  our  limits,  and  can  only  say  in  conclusion  that  Liston’s  Lec- 
tures, with  Mutter’s  additions,  should  be  in  every  surgeon’s  library,  and  in  every  student’s  hands,  who  wishes 
to  post  up  his  surgical  knowledge  to  the  present  moment.” — The  New  York  Journal  of  Medicine. 

“ These  lectures  will  be  found  eminently  practical,  a point  of  no  small  moment  in  a work 
on  Surgery.  Indeed,  we  have  no  hesitation  in  affirming,  that  it  is  a compendium  of  the 
modern  practice  of  Surgery  as  complete  and  accurate  as  any  treatise  of  similar  dimensions 
in  the  English  language. — The  Western  Lancet . 

Lately  Published,  a New  and  Much  Improved  Edition  of 

DRUITT’S  SURGERY. 

THE  PRINCIPLES  AND  PRACTICE  OF  MODERN  SURGERY, 

By  ROBERT  DRUITT,  Surgeon. 

FROM  THE  THIRD  LONDON  EDITION. 

ILLUSTRATED  BY  ONE  HUNDRED  AND  FIFTY-THREE  WOOD  ENGRAVINGS. 

WITH  NOTES  AND  COMMENTS, 

By  JOSHUA  B.  FLINT,  M.  M.,  S.  S. 

In  One  Volume,  Octavo. 

“An  unsurpassable  compendium  not  only  of  surgical  but  of  medicaj  nractice.” — London 
Medical  Gazette. 


3 


LEA  & BLANCHARD’S  PUBLICATIONS. 


BRODIE’S  SURGICAL  WORKS. 


NOW  READY, 

CLINICAL  LECTURES  ON  SURGERY, 

DELIVERED  AT  ST.  GEORGE’S  HOSPITAL 

By  SIR  BENJAMIN  BRODIE,  Bart.,  Y.  P.  R.  S„ 

SERJEANT  SURGEON  TO  THE  QUEEN,  ETC.  ETC. 

IN  ONE  NEAT  OCTAVO  VOLUME. 

These  Lectures,  in  passing  through  the  columns  of  “The  Medical  News,”  during  the 
last  year,  have  received  the  unanimous  approbation  of  the  profession  in  this  country,  and 
will  no  doubt  be  eagerly  sought  for  in  their  complete  state. 

“ Sir  Benjamin  Brodie  has  long  been  distinguished  as  a surgeon,  even  among  those  in  the  front 
rank,  and  may  now  he  regarded  as  occupying  the  first  place  in  Great  Britain,  if  not  in  the  world. 
It  is  not  as  a mere  operator  that  he  is  distinguished — that,  it  must  be  conceded  by  all  right  thinking 
minds,  is  but  a very  humble  part  of  the  qualifications  of  a surgeon — but  as  a profound  pathologist 
and  therapeutist.  We  may  be  prejudiced  or  mistaken,  but  in  these  higher  and  really  intellectual 
qualifications,  we  know  of  no  living  surgeon  that  approaches  him.  His  well  considered  opinions 
and  practical  instructions  are  conveyed,  too,  in  language  so  appropriate,  so  simple,  clear  and  chaste, 
that  one  scarcely  knows  whether  most  to  admire  the  excellence  of  the  matter  or  the  beauty  of  the 
style  in  which  it  is  clothed.  Theory  and  practice  go  hand  in  hand  throughout.  Rarely  is  a pre- 
cept given  without  being  illustrated  by  some  apposite  case,  selected  from  his  vast  experience,  and 
always  in  the  fewest  and  most  expressive  words.  Nothing  more  than  is  necessary  to  enforce  the 
point  is  said,  and  nothing  that  is  necessary  is  left  untold.” — The  Medical  Examiner. 

' “ It  would  not  be  easy  to  find  in  the  same  compass  more  useful  matter  than  is  embraced  in  each 
of  these  discourses,  or  indeed  in  this  volume.  We  the  less  regret  the  limited  extracts  we  have  it 
in  our  power  to  make  from  it,  because  we  feel  sure  that  it  will  in  a short  time  find  its  way  into  all 
the  medical  libraries  in  the  country.’ — The  Western  Journal  of  Medicine  and  Surgery. 

“ Sir  B.  Brodie  has  rendered  his  clinical  lectures — what  all  clinical  lectures  should  be — clear, 
impressive  and  practical  expositions  of  curative  measures,  in  which  all  the  most  important  features 
of  the  subject  are  plainly  set  forth,  without  being  unnecessarily  encumbered  with  details.  We 
attach  a very  high  value  to  these  Lectures:  their  style  is  clear,  demonstrative  and  unaffected,  de- 
cided and  energetic ; hut  altogether  free  from  dogmatism  or  over-confidence.  They  are  strictly 
practical ; and  much  of  the  information  which  they  contain  will  assuredly  do  the  reader  and  his 
patients  good  service  in  time  of  need.” — Medical  Gazette. 


BRODIE  ON  URINARY  ORGANS, 


LECTURES 

ON  THE  DISEASES  OF  THE  URINARY  ORGANS. 

FROM  THE  THIRD  LONDON  EDITION. 

WITH  ALTERATIONS  AND  ADDITIONS. 

In  One  Small  Octavo  Volume,  Cloth. 

This  work  has  been  entirely  revised  throughout,  some  of  the  author’s  views  have  been 
modified,  and  a considerable  proportion  of  new  matter  has  been  added,  among  which  is 
a lecture  on  the  Operation  of  Lithotomy. 

BRODIE  ON  THE  JOINTS, 


PATHOLOGICAL  AND  SURGICAL  OBSERVATIONS 

ON  THE  DISEASES  OF  THE  JOINTS. 

FROM  THE  FOURTH  LONDON  EDITION. 

2®mii  the  Author’s  Alterations  anh  AtHHtlons. 

In  One  Small  Octavo  Volume,  Cloth. 

r “To  both  the  practical  physician  and  the  student,  then,  this  little  volume  will  be  one  of  much 
service,  inasmuch  as  we  have  here  a condensed  view  of  these  complicated  subjects  thoroughly 
investigated  by  the  aid  of  the  light  afforded  by  modern  Pathological  Surgery.” — N.  Y.  Journal  of 
Medicine. 


LEA  & BLANCHARD’S  PUBLICATIONS.  9 

THE  SIXTH  EDITION  OF  DUNGLISON’S  MEDICAL  DICTIONARY. 

To  1846. 

medicaiTlexicon, 

A DICTIONARY 

OF 

MEDICAL  SCIENCE. 

CONTAINING 

A CONCISE  ACCOUNT  OF  THE  VARIOUS  SUBJECTS  AND  TERMS  ; WITH 
THE  FRENCH  AND  OTHER  SYNONYMES  ; NOTICES  OF  CLIMATES 
AND  OF  CELEBRATED  MINERAL  WATERS;  FORMULA! 

FOR  VARIOUS  OFFICINAL  AND  EMPIRICAL  PREPA- 
RATIONS, &c. 

BY  ROBLEY  DUNGLISON,  M.  D., 

Professor  of  the  Institutes  of  Medicine,  &c.  in  Jefferson  Medical  College,  Philadelphia. 

SIXTH  EDITION,  REVISED  AND  GREATLY  ENLARGED. 

In  one  Royal  Octavo  Volume  of  over  800  very  large  pages,  double  columns. 
Strongly  bound  in  the  best  leather,  raised  bands. 

It  is  not  necessary  for  the  author  to  say  more,  as  a preface  to  this  sixth  edition  of  his  dictionary,  than  that  he 
has  bestowed  the  same  care  on  its  revision  and  improvement,  which  he  did  on  the  others,  In  proof  of  this,  he 
may  remark,  that  the  present  edition  comprises  nearly  two  thousand  Jive  hundred  subjects  and  terms  not  con- 
tained in  the  last.  Many  of  these  have  been  introduced  into  ipedical  terminology  in  consequence  of  the  pro- 
gress of  the  science  ; and  others  had  escaped  him  in  previous  revisions. 

It  is  the  author’s  anxious  wish  to  render  the  work  a satisfactory  and  desirable — if  not  indispensable — Lexicon, 
in  which  the  student  may  search  without  disappointment  for  every  term  that  has  been  legitimated  in  the  nomen- 
clature of  the  science.  This  desideratum  he  is  enabled  to  attempt  in  successive  editions,  by  reason  of  the  work 
not  being  stereotyped;  and  the  present  edition  certainly  oiTers  stronger  claims  to  the  attention  of  the  practi- 
tioner and  student  than  any  of  its  predecessors.—  Preface  to  Sixth  Edition , May  1846. 

A NEW  EDITION  OF 

THE  MEDICAL  STUDENT, 

OR  AIDS  TO  THE  STUDY  OF  MEDICINE. 

A REVISED  AND  MODIFIED  EDITION. 

BY  ROBLEY  DUNGLISON,  M.  D., 

In  One  neat  12mo.  volume. 


HUMAN  HEALTH; 

OR,  THE  INFLUENCE  OF  ATMOSPHERE  AND  LOCALITY,  CHANGE  OF  AIR 
AND  CLIMATE,  SEASONS,  FOOD,  CLOTHING,  BATHING  AND  MINE- 
RAL SPRINGS,  EXERCISE,  SLEEP,  CORPOREAL  AND  INTEL- 
LECTUAL PURSUITS,  &'c.  &c.,  ON  HEALTHY  MAN: 
CONSTITUTING 

ELEMENTS  OF  HYGIENE. 

BY  ROBLEY  D U N G L I S 0 N,  M.  D. 

A New  Edition  with  many  Modifications  and  Additions.  In  One  Volume,  8vo. 

DUNGLISON  ON  NEW,  REMEDIES. 

NEW  R EM E DIES, 

PHARMACEUTICALLY  AND  THERAPEUTICALLY  CONSIDERED. 
FOURTH  EDITION. 

WITH  EXTENSIVE  MODIFICATIONS  AND  ADDITIONS, 

BY  ROBLEY  DUNGLISON,  M.D.,  &c. 

The  numerous  valuable  therapeutical  agents  which  have  of  late  years  been  introduced  into  the  Materia 
Medica,  render  it  a difficult  matter  for  the  practitioner  to  keep  up  with  the  advancement  of  the  science,  espe- 
cially as  the  descriptions  of  them  are  difficult  of  access,  being  scattered  so  widely  through  transactions  of 
learned  societies,  journals,  monographs,  &c.  &c.  To  obviate  this  difficulty,  and  to  place  within  reach  of  the 
profession  this  important  information  in  a compendious  form,  is  the  object  of  the  present  volume,  and  the  num- 
ber of  editions  through  which  it  has  passed  show  that  its  utility  has  not  been  underrated. 

ITT*  Apothecaries  and  Physicians  may  rely  upon  having  a late  edition  of  this  useful  work. 


10 


LEA  & BLANCHARD’S  PUBLICATIONS. 


PROFESSOR  DUNGLISON’S  WORKS. 


NOW  READY— A NEW  EDITION  OF 

DUNGLISON’S  PHYSIOLOGY, 

Brought  up  to  1846. 


HUMAN  PHYSIOLOGY, 

WITH 

THREE  HUNDRED  AND  SEVENTH  ILLUSTRATIONS. 

BY  ROBLEY  DUNGLISON,  M.  D., 

TEOFESSOR  OF  THE  INSTITUTES  OF  MEDICINE  IN  THE  JEFFERSON  MEDICAL  COLLEGE,  PHILADELPHIA, 

&C.  &C. 

S I X T PI  EDITION. 

GREATLY  IMPROVED. 

In  two  large  octavo  volumes,  containing  nearly  1350  pages. 

“ It  is  but  necesary  for  the  Author  to  say  that  all  the  cares  that  were  bestowed 
on  the  preparation  of  the  fifth  edition  have  been  extended  to  the  sixth,  and  even 
to  a greater  amount.  Nothing  of  importance  that  has  been  recorded  since  its 
publication,  has,  he  believes,  escaped  his  attention.  Upwards  of  seventy  illustra- 
tions have  been  added ; and  many  of  the  former  cuts  have  been  replaced  by  others. 
The  work,  he  trusts  will  be  found  entirely  on  a level  with  the  existing  advanced 
state  of  physiological  science.” 

In  mechanical  and  artistical  execution,  this  edition  is  far  in  advance  of  any  former  one.  The 
illustrations  have  been  subjected  to  a thorough  revision,  many  have  been  rejected  and  their  places 
supplied  with  superior  ones,  and  numerous  new  wood-cuts  have  been  added  wherever  perspicuity  or 
novelty  seemed  to  require  them. 


THE  PRACTICE  OF  MEDICINE, 

OR  A TREATISE  ON 

SPECIAL  PATHOLOGY  AND  THERAPEUTICS. 

BY  ROBLEY  DUNGLISON,  M.  D. 

CONTAINING 

THE  DISEASES  OF  THE  ALIMENTARY  CANAL,  THE  DISEASES  OF  THE 
CIRCULATORY  APPARATUS,  DISEASES  OF  THE  GLANDULAR  OR- 
GANS, DISEASES  OF  THE  ORGANS  OF  THE  SENSES,  DISEASES 
OF  THE  RESPIRATORY  ORGANS,  DISEASES  OF  THE  GLAN- 
DIFORM GANGLIONS,  DISEASES  OF  THE  NERVOUS  SYS- 
TEM, DISEASES  OF  THE  ORGANS  OF  REPRODUC- 
TION, DISEASES  INVOLVING  VARIOUS  ORGANS, 

&c.  &c. 

In  Two  Volumes,  Octavo. . 

This  work  has  been  introduced  as  a text-book  in  many  of  the  Medical  Colleges, 
and  the  general  favor  with  which  it  has  been  received,  is  a guarantee  of  its  value 
to  the  practitioner  and  student. 

“ In  the  volumes  before  us.  Dr.  Dunglison  has  proved  that  his  acquaintance  with  the  present  facts 
and  doctrines,  wheresoever  originating,  is  most  extensive  and  intimate,  and  the  judgment,  skill, 
and  impartiality  with  which  the  materials  of  the  work  have  been  collected,  weighed,  arranged,  and 
exposed,  are  strikingly  manifested  in  every  chapter.  Great  care  is  everywhere  taken  to  indicate 
the  source  of  information,  and  under  the  head  of  treatment,  formulae  of  the  most  appropriate  reme- 
dies are  everywhere  introduced.  In  conclusion,  we  congratulate  the  students  and  junior  practi- 
tioners of  America  on  possessing  in  the  present  volumes  a work  of  standard  merit,  to  which  they 
may  confidently  refer  in  their  doubts  and  difficulties.” — Brit,  and  For.  Med.  Rev.  for  July,  1842. 

“ Since  the  foregoing  observations  were  written,  we  have  received  a second  edition  of  Dungli- 
son’s  work,  a sufficient  indication  of  the  high  character  it  has  already  attained  in  America,  and 
justly  attained.” — Ibid,  for  October,  1844. 


LEA  & BLANCHARD’S  PUBLICATIONS. 


11 


NOW  READY, 

DUNGLISON’S  THERAPEUTICS. 

A NEW  EDITION,  MUCH  IMPROVED,  TO  1846. 


GENERAL  THERAPEUTICS  AND  MATERIA  MEDICA. 

WITH  ONE  HUNDRED  AND  TWENTY  ILLUSTRATIONS. 

ADAPTED  FOR  A MEDICAL  TEXT-BOON. 

BY  ROBLEY  DUNGLISON,  M.D., 

Professor  of  Institutes  of  Medicine,  etc.  in  Jefferson  Medical  College;  Late  Professor  of  Materia  Medica,  etc. 
in  the  Universities  of  Virginia  and  Maryland,  and  in  Jefferson  Medical  College. 

Third  Edition,  Revised  and  Improved,  in  Two  Octavo  Volumes,  well  hound . 

In  this  edition  much  improvement  will  be  found  over  the  former  ones.  The  author  has  subjected 
it  to  a thorough  revision,  and  has  endeavored  to  so  modify  the  work  as  to  make  it  a more  complete 
and  exact  exponent  of  the  present  state  of  knowledge  on  the  important  subjects  of  which  it  treats. 
The  favor  with  which  the  former  editions  were  received,  demanded  that  the  present  should  be  ren- 
dered still  more  worthy  of  the  patronage  of  the  profession,  and  this  alteration  will  be  found  not 
only  in  the  matter  of  the  volumes,  but  also  in  the  numerous  illustrations  introduced,  and  the  gene- 
ral improvement  in  the  appearance  of  the  work. 


LIST  OF  ILLUSTRATIONS.— Vol.  I. 

1.  Cephaelis  Ipecacuanha.  17.  Legume  and  leaflet  of  C.  37.  Celraria  Tslandica.  57.  Lycopus  Virginicus. 

2.  Brown  Ipecacuan.  root.  obovata.  38.  Fucus  vesiculosus.  5S.  Strychnos  Nux  Vomica. 

3.  Striated  ipecacuan.  root  IS.  Tinnevelly  Senna.  39  Inhaler.  59.  Ruta  graveolens. 

— Undulated  Ipecacu-  19.  Cassia  Marilandica.  40.  Cantharides.  GO.  Secale  eornutuin. 

anh a root.  20.  Podophyllum.  41.  Leontodon  Taraxacum.  61.  Cinnamomum  Zeylani- 

4.  Tonidium  Ipecac,  root.  21.  Hebradendroncambogi-42.  Erigeron  Philadelphi-  cum. 

5.  Gillenia  stipulacea.  o'ides.  cum.  62.  Cardamom. 

6.  Lobelia  inflata.  22.  Momordica  Elatermm.  43.  Arbutus  Uva  ursi.  63.  Cariophyllus  aromaticus 

7.  Sanguinaria  Canadensis  23.  Apocynum  cannabinum  44.  Eupaiorium  perfoliatum.  64.  Fceniculum  vidgare. 

8.  Apocynum  Androsaemi-  24.  Convolvulus panduratus45.  Asclepias  tuberosa.  65.  Monarda  coccinea. 

folium.  25.  Chenopodium  Anthel-  46.  Arum  triphyllum. 

9.  Erythronium  America-  minticum.  47.  Carthamus  tinclorius. 

num.  26.  Spigelia  Marilandica.  48.  Warm-bath. 

10.  Euphorbia  corollata.  27.  Nephrodium  Filix  max.  49.  Hip-bath. 

2S.  Punica  granatum.  50.  Foot-bath. 

29,  30.  Inhaling  Bottles.  5L.  Hyoscyamus  Niger. 

31.  Balsamadend’n  Myrrha.  52.  Datura  Stramonium. 

32.  Acacia  Arabica.  53.  Conium  maculatum. 

33.  Olea  Europaea.  54.  Humulus  Lupulus. 

16.  Legume  and  leaflet  of 34.  Saccharum  officinarum.55.  Dried  lupulinic  grain74  Acorus  Calamus. 

Acute  leaved  Alexan-  35.  Linum  usitatissimum.  with  its  hilum  magnifi’d  75.  Piper  nigrum. 


11.  Ficus  Carica. 

12  Ricinis  communis. 

13.  Rheum  palmatum. 

14.  Rheum  compactum. 

15.  Aloe  Socotorina. 


66.  Hedeoma  pulegioides. 

67.  JVlyristica  moschata. 

68.  Nutmeg  in  ihe  shell  sur- 

rounded by  the  mace. 

69.  Gaultheria  procumbens. 
70.,Jimiperus  communis. 

71.  Citrus  Aurantium. 

72.  Laurus  camphora. 

73  Drymis  Winieri. 


drian  Senna. 


36.  Astragalus  verus. 


56.  Cannabis  sativa. 


76.  Electrical  Apparatus  for 
Medical  purposes. 


35.  Panic’s  of  Potato  starch 
seen  by  the  microscope. 

36.  Jaqipha  Manihot. 

37.  Particles  of  Tapioca  as 
seen  by  the  microscope. 


VOL.  II. 

13.  Tlepatica  Americana.  26.  Abies  excelsa. 

14.  Indigo.  27.  Ranunculus  acris. 

15.  Cornus  Florida.  28.  Aralia  nudicaulis. 

16.  Liriodendron  tulipifera  29.  Solanum  dulcamara. 

17.  Dyospyros  Virgiijiana.  30.  Tacca  pinnatifida. 

18.  Heuchera  acerifolia.  31.  Particles  of  Tahiti  Ar-38.  Sagus  Rumphii. 

19  Spirsea  tomentosa.  row-root.  39  Particles  of  Sago-meal. 

7.  Aristolochiaserpentaria20.  Statice  Caroliniana.  32.  Particles  of  white  East  40.  Particles  of  Potato  sago. 

8.  Asarum  Canadense.  21.  Colchicum  autumnale.  India  Arrow-root.  41.  Cycas  revoluta  or  the 

9.  Anthemis  Cotula.  22.  Veralrnm  Album.  Var.  33.  Particles  of  West  India  Japan  Sagonree. 

10.  Magnolia  glauca.  Albiflorum.  Arrow-root.  42  Avena  Sativa. 

11.  Magnolia  macrophylla.  23.  Cim  cifuga  racemosa.  34.  Particles  of  Tous-les-  43.  Parti’s  of  Wheat  Starch 

12.  Geum  Virginianum.  24, 25.  Shower-bath.  mois. 

“Our  junior  brethren  in  America  will  find  in  these  volumes  of  Professor  Dunglison,  a ‘Thesaurus  Medica* 
Minum,’  more  valuable  than  a large  purse  of  gold.” — Medico- Chirurgical  Review  for  Jan.  1845. 


1.  Cocculus  palmatus. 

(Male  plant.) 

2.  Gentiana  Catesbaei. 

3.  Frasera  Walteri. 

4 Sabbatia  angularis. 

5.  Coptis  trifolia. 

6.  Aletris  farinosa. 


ELLIS’S  MEDICAL  FGK.MULAH1T, 

NEW  AND  IMPROVED  EDITION,  TO  JULY,  1846. 

THE  MEDICAL  FORMULARY: 

BEING  A COLLECTION  OE  PRESCRIPTIONS,  DERIVED  FROM  THE  WRITINGS  AND  PRACTICE  OF  MANY  OF 
THE  MOST  EMINENT  PHYSICIANS  OF  AMERICA  AND  EUROPE. 

TO  WHICH  IS  ADDED  AN  APPENDIX, 

CONTAINING  THE  USUAL  DIETETIC  PREPARATIONS  AND  ANTIDOTES  FOR  POISONS. 

THE  WHOLE  ACCOMPANIED  WITH  A FEW  BRIEF  PHARMACEUTIC  AND  MEDICAL  OBSERVATIONS. 

BY  BENJAMIN  ELLIS,  M . D., 

Late  Professor  of  Materia  Medica  and  Pharmacy  in  the  Philadelphia  College  of  Pharmacy. 

EIGHTH  EDITION,  WITH  EXTENSIVE  ALTERATIONS  AND  ADDITIONS. 

BY  SAMUEL  GEORGE  MORTON,  M.  D. 

In  One  neat  Octavo  Volume. 

This  popular  work  has  been  too  extensively  and  favorably  known  to  the  profession  in  the  United  States  to 
require  any  remarks  in  introducing  a new  edition,  except  to  state  that  the  improvements  in  it  will  be  found  to 
be  numerous  and  important.  Great  care  has  been  taken  in  its  passage  through  the  press  to  insure  the  utmost 
accuracy,  and  it  is  confidently  presented  as  worthy  the  increased  confidence  of  physicians  and  apothecaries. 


12 


LEA  & BLANCHARD’S  PUBLICATIONS. 


HASSE’S  PATHOLOGICAL  ANATOMY. 


AN  ANATOMICAL  DESCRIPTION 

OP  THE  DISEASES  OF  THE 

ORGANS  OF  CIRCULATION  ANO  RESPIRATION. 

BY  CHARLES  EWALD  HASSE, 

Professor  of  Pathology  and  Clinical  Medicine  in  the  University  of  Zurich,  &c. 
TRANSLATED  AND  EDITED  BY 

W.  E.  S W A I N E,  M.  D.,  &c. 

In  one  octavo  volume. 

A KTew  Work,  Just  Ready.— July  1846. 

HOPE  ON  THE  HEART,— New  Edition. 

A TREATISE  ON  THE  DISEASES 

OF  THE  HEART  AND  GREAT  VESSELS, 

AND  ON  THE  AFFECTIONS  WHICH  MAY  BE  MISTAKEN 

FOR  THEM. 

COMPRISING  THE  AUTHOR’S  VIEW  OF  THE  PHYSIOLOGY  OF  THE  HEART’S 
ACTION  AND  SOUNDS  AS  DEMONSTRATED  BY  HIS  EXPERIMENTS 
ON  THE  MOTIONS  AND  SOUNDS  IN  1830,  AND  ON  THE 
SOUNDS  IN  1S34-5. 

BY  J.  HOPE,  M.D.,  F.R.S.,  &c.  &c, 

Second  American  from,  the  Third  London  Edition. 

WITH  NOTES  AND  A DETAIL  OE  RECENT  EXPERIMENTS. 

BY  C.  W.  PENNOCK,  M.D.,  &c. 

In  one  octavo  volume  of  nearly  600  pages,  with  lithographic  plates. 

HUGHES  ON  THE  LUNGS  AND  HEART. 

CLINICAL  INTRODUCTION  TO  TEE  PRACTICE  OF  AUSCULTATION, 

AND  OTHER  MODES  OF  PHYSICAL  DIAGNOSIS. 

INTENDED  TO  SIMPLIFY  THE  STUDY  OF  THE  DISEASES  OF  THE  HEART 

AND  LUNGS. 

BY  H.  M.  HUGHES,  M.D.,  &c. 

In  One  Duodecimo  Volume,  with  a plate. 

A NEW  WORK.— PHILLIPS  ON  SCROFULA. 

JUST  11E.II>  \\ — July  1846. 

SCR  0~F  U L A, 

ITS  NATURE,  ITS  PREVALENCE,  ITS  CAUSES,  AND  THE  PRINCIPLES  OF 

ITS  TREATMENT. 

BY  BENJAMIN  PHILLIPS,  M.  D.,  F.  R.  S.,  &c. 

In  one  neat  octavo  volume , with  a plate. 

u There  can  be  no  doubt  that  there  was  ample  room  for  a fresh  review  of  scrofula,  and  that  a work  on  tho 
subject,  from  a writer  of  learning,  industry,  and  talent,  must  be  acceptable;  and  such,  after  a careful  perusal, 
the  work  before  us  appears  to  be.  Very  uncommon  pains  seem  to  have  been  taken  in  collecting  information 
from  men  as  well  as  hooks.  Our  impression  of  this  work  is,  that  it  is  a very  important  accession  to  our  profes- 
sional literature,  and  does  the  greatest  credit  to  the  industry,  research  and  talent  of  the  author.  Its  utility  is, 
we  think,  likely  to  extend  far  beyond  the  limits  of  professional  society.” — The  London  Medical  Gazette. 

This  work  is  just  published.  The  author  has  been  for  years  engaged  in  the  collection  of  materials  and  sta- 
tistics from  all  parts  of  the  world. 


SMALL  BOOKS  ON  GREAT  SUBJECTS. 


.v«  u ’ re. id  i*, 

“The  Connection  between  Physiology  and  Intellectual  Science.” 

Forming  No.  2 of  a series  of  small  works  now  issuing  at  Twenty-five  Cents  each. 

To  be  followed  shortly  by  “ Philosophical  Theories  and  Philosophical  Experience,” — On  Man’s 
Power  over  Himself  to  Prevent  or  Control  Insanity,” — “An  Introduction  to  Practical  Organic  Che- 
mistry,”— “An  Introduction  to  Vegetable  Physiology,  with  References  to  the  Works  of  De  Can- 
dolle, Lindley,  &c.,”  and  several  other  new  and  valuable  works.  Each  one  to  form  a very  neat 
and  portable  volume. 

OCr  These  works  have  acquired  great  popularity  in  England,  and  the  publishers  take  pleasure 
in  introducing  the  series  neatly  printed,  and  at  so  low  a price. 


LEA  & BLANCHARD’S  PUBLICATIONS. 


13 


COMPENDIUM  OF  CHAPMAN’S  LECTURES. 

A COMPENDIUM  OF  LECTURES 

ON  THE 

THEORY  AND  PRACTICE  OF  MEDICINE. 

DELIVERED  BY  PROFESSOR  CHAPMAN  IN  THE  UNIVERSITY  OF  PENN- 
SYLVANIA. 

PREPARED.  WITH  PERMISSION.  FROM  DR.  CHAPMAN’S  MANUSCRIPTS, 
AND  PUBLISHED  WITH  HIS  APPROBATION, 

BY  N.  D.  BENEDICT,  M.  D. 

IN  ONE  VERY  NEAT  OCTAVO  VOLUME. 

CONTENTS. 

Remarks  on  the  Classification  ofDiseases — Feverin  General — Intermittent  Fever — Remittent  Fever 
■ — Continued  Fever,  (Mild,  Intermediate,  and  Extreme  Forms) — Yellow  Fever — Endemic  Pneu- 
monic, or  Spotted  Fever — Diseases  of  the  Heart  and  Blood-vessels,  (Inflammatory,  Organic,  and 
Nervous) — Acute  Carditis,  Pericarditis,  and  Endocarditis — Chronic  Carditis,  Pericarditis,  and  En- 
docarditis— Hypertrophy  of  the  Heart — Dilatation  of  the  Heart — Atrophy  of  the  Heart — Rupture 
of  the  Heart — Affections  of  the  Valves  of  the  Heart — Palpitations — Acute  Arteritis — Degenera- 
rations  of  Arteries — Aneurism  of  Arteries — Phlebitis — Acute  Inflammation  of  the  Throat — Chronic 
Inflammation  of  the  Throat — Dysphagia — Parotitis — Dysentery,  (Inflammatory) — Dysentery,  (Con- 
gestive)— Diarrhoea — Cholera  Morbus — Cholera  Infantum — Flatulent  Colic — Bilious  Colic- — Colica 
Pictonum — Acute  Peritonitis — Chronic  Peritonitis — Acute  Catarrh — Catarrhus  jEstivus— Chronic 
Catarrh — Acute  Bronchitis — Chronic  Bronchitis — Catarrhus  Senilis — Acute  Infantile  Bronchitis — 
Chronic  Infantile  Bronchitis — Croup — Acute  Infantile  Asthma — Whooping-Cough — Acute  Laryn- 
gitis— Chronic  Laryngitis — Pleuropneumonia — Congestive  Pneumonia — Chronic  Pleurisy  and 
Pneumonia — Apoplexy — Palsy — Epilepsy — Hysteria — Chorea — Neuralgia — Diabetes. 

The  subjects  treated  of  in  this  volume  are  entirely  distinct  from  those  considered  in  Dr. 
Chapman’s  two  works  on  “Thoracic  and  Abdominal  Viscera,”  and  on  “Eruptive  Fevers,” 
&c.  These  works  are  all  printed  and  bound  to  match,  and  form  three  very  neat  octavo 
volumes. 


LECTURES  ON  THE  MORE  IMPORTANT  DISEASES 

OF  THE 

THORACIC  AND  ABDOMINAL  VISCERA. 

DELIVERED  IN  THE  UNIVERSITY  OF  PENNSYLVANIA. 

BY  N.  CHAPMAN,  M.  D. 

PROFESSOR  OF  THE  THEORY  AND  PRACTICE  OF  MEDICINE,  ETC. 

In  One  Volume,  Octavo. 

CHAPMAN  OfT~FEVERS,  &c. 

LECTURES  ON  THE  MORE  IMPORTANT 

ERUPTIVE  FEVERS,  HAEMORRHAGES  AND  DROPSIES, 

AND  ON  GOUT  AND  RHEUMATISM, 

DELIVERED  IN  THE  UNIVERSITY  OF  PENNSYLVANIA. 

By  N.  CHAPMAN,  M.D., 

PROFESSOR  OF  THE  THEORY  AND  PRACTICE  OF  MEDICINE,  ETC.  ETC. 

In  One  Neat  Octavo  Volume. 

“ The  name  of  Chapman  stands  deservedly  high  in  the  annals  of  American  medical  science.  A teacher  anil 
a lecturer  for  nearly  forty  years,  in  the  oldest  and,  we  believe,  the  first  medical  school  on  this  side  of  the  At- 
lantic, the  intimate  friend  and  companion  of  Rush,  Kuhn,  Physick,  Wislar,  Woodhouse,  Dewees,  and  a host 
of  others,  scarcely  less  renowned,  Professor  Chapman  reflects  upon  the  profession  of  this  generation  something 
of  the  genius  and  wisdom  of  that  which  has  passed ; he  stands  out  the  able  and  eloquent  champion  of  the  doc- 
trines and  principles  of  other  times,  when  Cullen’s  “ first  lines”  formed  the  rule  of  faith  for  all  the  Doctors  in 
Medicine  throughout  Christendom.  In  him  is  embodied  the  experience  of  three  score  and  ten,  strengthened 
by  reading,  and  enlightened  by  a familiar  intercourse  with  many  of  the  ablest  medical  men  in  the  New  and 
Old  World.  In  conclusion,  we  must  declare  our  belief  that  the  name  of  Chapman  will  survive  when  that  of 
many  of  his  cotemporaries  shall  have  been  forgotten  ; when  other  generations  shall  tread  the  great  theatre  of 
human  affairs,  and  when  other  discoveries  yet  undisclosed,  shall  shed  a brighter  light  upon  the  path  of  medi- 
cal science.  The  various  lectures  which  he  has  been  publishing,  containing,  as  they  do,  the  doctrines  that 
he  has  so  long  and  so  eloquently  taught  to  large  and  admiring  classes,  we  doubt  not  will  be  welcomed  with 
delight  by  his  numerous  pupils  throughout  the  Union.”— Netc  Orleans  Medical  Journal. 


14 


LEA  & BLANCHARD’S  PUBLICATIONS. 


HORNER’S  ANATOMY, 

NEW  EDITION— To  be  Ready  by  October. 


SPECIAL  ANATOMY 

AND 

HISTOLOGY. 

BY 

WILLIAM  E.  HORNER,  M.  D., 

PROFESSOR  OF  ANATOMY  IN  THE  UNIVERSITY  OF  PENNSYLVANIA,  &c.  &c. 

SEVENTH  EDITION, 

WITH  MANY  IMPROVEMENTS  AND  ADDITIONS. 

In  two  Octavo  Volumes,  ivith  Illustrations  on  Wood. 

This  standard  work  has  been  so  long  before  the  profession,  and  has  been 
so  extensively  used,  that,  in  announcing  the  new  edition,  it  is  only  neces- 
sary to  state  that  it  will  undergo  a most  careful  revision  ; the  author  will 
introduce  many  illustrations  relating  to  Microscopical  Anatomy,  and  will 
add  a large  amount  of  text  on  these  various  points  of  investigation  that 
are  rapidly  advancing  and  attracting  so  much  attention.  Tins  new  edi- 
tion will  be  arranged  to  refer  conveniently  to  the  illustrations  in  Smith 
and  Horner’s  Anatomical  Atlas,  and  will  be  ready  for  the  Fall  Lectures. 

HORNER’S  DISSECTOR. 

THE  UNITED  STATES  DISSECTOR, 

BEING  A NEW  EDITION,  WITH  EXTENSIVE  MODIFICATIONS,  AND 
ALMOST  REWRITTEN, 

OF 

“HORNER’S  PRACTICAL  ANATOMY.” 

IN  ONE  VERY  NEAT  VOLUME, 

ROYAL  12mo. 

With  many  Illustrations  on  Wood. 

The  numerous  alterations  and  additions  which  this  work  has  under- 
gone, the  improvements  which  have  been  made  in  it,  and  the  numerous 
wood-cuts  which  have  been  introduced,  render  it  almost  a new  work. 

It  is  the  standard  work  for  the  Students  in  the  University  of  Pennsyl- 
vania. 

BUDD  ON  THE  LIVER. 

ON  DISEASES  OF  THE  LIVER. 

BY  GEORGE  BUDD,  M.D.,  F.R.S., 

Professor  of  Medicine  in  King’s  College,  London,  &c.  &c. 

With  colored  plates,  and  numerous  wood-cuts.  In  one  neat  octavo  volume. 
i:  We  cannot  too  strongly  recommend  llie  diligent  study  of  tliis  volume.  The  work  cannot  fail  to  rank  the 
name  of  its  author  among  the  most  enlightened  pathologists  and  soundest  practitioners  of  the  day.”— Medico- 
Cltirurgical  Review. 


A MLA GNTFICENT  AND  CHEAP  WOES. 

SMITH  & HORNER’S  ANATOMICAL  ATLAS. 

Just  Published,  Price  Five  Dollars  in  Parts. 


AN 

ANATOMICAL  ATLAS 
ILLUSTRATIVE  OF  THE  STRUCTURE  OF  THE  HUMAN  BODY. 

BY  HENRY  H.  SMITH,  M.  D., 

Fellow  of  the  College  of  Physicians,  $c. 

UNDER  THE  SUPERVISION  OF 

WILLIAM  E.  HORNER,  M.  D., 

Professor  of  Anatomy  in  the  University  of  Pennsylvania. 

In  One  large  Volume,  Imperial  Octavo. 

This  work  is  but  just  completed,  having  been  delayed  over  the  time  intended  by  the  great  difficulty  in  giving 
to  the  illustrations  the  desired  finish  and  perfection.  It  consists  of  five  parts,  whose  contents  are  as  follows : 

Part  I.  The  Bones  and  LigamentSj  with  one  hundred  and  thirty  engravings. 

Part  II.  The  Muscular  and  Dermoid  Systems,  with  ninety-one  engravings. 

Part  III.  The  Organs  of  Digestion  and  Generation,  with  one  hundred  and  ninety-one  engravings. 

Part  IV.  The  Organs  of  Respiration  and  Circulation,  with  ninety-eight  engravings. 

Part  V.  The  Nervous  System  and  the  Senses,  with  one  hundred  and  twenty-six  engravings. 

Forming  altogether  a complete  System  of  Anatomical  Plates,  of  nearly 

SIX  HUNDRED  AND  FIFTY  FIGURES, 

executed  in  the  best  style  of  art,  and  making  one  large  imperial  octavo  volume.  Those  who  do  not  want  it  m 
parts  can  have  the  work  bound  in  extra  cloth  or  sheep  at  an  extra  cost. 

This  work  possesses  novelty  both  in  the  design  and  the  execution.  It  is  the  first  attempt  to  apply  engraving 
on  wood,  on  a large  scale,  to  the  illustration  of  human  anatomy,  and  the  beauty  of  the  parts  issued  induces  the 
publishers  to  flatter  themselves  with  the  hope  of  the  perfect  success  of  their  undertaking.  The  plan  of  the 
work  is  at  once  novel  and  convenient.  Each  page  is  perfect  in  itself,  the  references  being  immediately  under 
the  figures,  so  that  the  eye  takes  in  the  whole  at  a glance,  and  obviates  the  necessity  of  continual  reference 
backwards  and  forwards.  The  cuts  are  selected  from  the  best  and  most  accurate  sources ; and,  where  neces- 
sary, original  drawings  have  been  made  from  the  admirable  Anatomical  Collection  of  the  University  of  Penn- 
sylvania. It  embraces  all  the  late  beautiful  discoveries  arising  from  the  use  of  the  microscope  in  the  investi- 
gation of  the  minute  structure  of  the  tissues. 

In  the  getting  up  of  this  very  complete  work,  the  publishers  have  spared  neither  pains  nor  expense,  and  they 
now  present  it  to  the  profession,  with  the  full  confidence  that  it  will  be  deemed  all  that  is  wanted  in  a scientific 
and  artistical  point  of  view,  while,  at  the  same  time,  its  very  low  price. places  it  within  the  reach  of  all. 

It  is  particularly  adapted  to  supply  the  place  of  skeletons  or  subjects , as  the  prof  ess  ion  will  see  by  examining  the  list 
of  plates 


M These  figures  are  well  selected,  and  present  a complete  and  accurate  representation  of  that  wonderful  fabric, 
the  human  body.  The  plan  of  this  Atlas,  which  renders  it  so  peculiarly  convenient  for  the  student,  and  its 
superb  artistical  execution,  have  been  already  pointed  out.  We  must  congratulate  the  student  upon  the 
completion  of  this  atlas,  as  it  is  the  most  convenient  work  of  the  kind  .that  has  yet  appeared;  and,  we  must 
add,  the  very  beautiful  manner  in  which  it  is  ‘ got  up5  is  so  creditable  to  the  country  as  to  be  flattering  to  our 
national  pride.” — American  Medical  Journal. 

“This  is  an  exquisite  volume,  and  a beautiful  specimen  of  art.  We  have  numerous  Anatomical  Atlases, 
but  we  will  venture  to  say  that  none  equal  it  in  cheapness,  and  none  surpass  it  in  faithfulness  and  spirit.  We 
strongly  recommend  to  our  friends,  both  urban  and  suburban,  the  purchase  of  .this  excellent  work,  for  which 
both  editor  and  publisher  deserve  the  thanks  of  the  profession.” — Medical  Examiner. 

“We  would  strongly  recommend  it,  not  only  to  the  student,  but  also  to  the  working  practitioner,  who, 
although  grown  rusty  in  the  toils  of  his  harness,  still  has  the  desire,  and  often  the  necessity,  of  refreshing  his 
knowledge  in  this  fundamental  part  of  the  science  of  medicine.” — New  York  Journal  of  Medicine  and  Surg. 

“ The  plan  of  this  Atlas  is  admirable,  and  its  execution  superior  to  any  thing  of  the  kind  before  published  m 
this  country.  It  is  a real  labour-saving  affair,  and  we  regard  its  publication  as  the  greatest  boon  that  could  be 
conferred  on  the  student  of  anatomy.  It  will  be  equally  valuable  to  the  practitioner,  by  affording  him  an  easy 
means  of  recalling  the  details  learned  in  the  dissecting  room,  and  which  are  soon  forgotten.” — American  Medi- 
cal Journal. 

“It  is  a beautiful  as  well  as  particularly  useful  design,  which  should  be  extensively  patronized  by  physicians, 
surgeons  and  medical  students.” — Boston  Med.  and  Surg.  Journal. 

“ It  has  been  the  aim  of  the  author  of  the  Atlas  to  comprise  in  it  the  valuable  points  of  all  previous  works,  to 
embrace  the  latest  microscopical  observations  on  the  anatomy  of  the  tissues,  and  by  placing  it  at  a moderate 
price  to  enable  all  to  acquire  it  who  may  need  its  assistance  in  the  dissecting  or  operating  room,  or  other  field 
of  practice.” — Western  Journal  of  Med.  and  Surgery. 

“These  numbers  complete  the  series  of  this  beautiful  work,  which  fully  merits  the  praise  bestowed  upon  the 
earlier  numbers.  We  regard  all  the  engravings  as  possessing  an  accuracy  only  equalled  by  their  beauty, 
and  cordially  recommend  the  work  to  all  engaged  in  the  study  of  anatomy.” — New  York  Journal  ofMedicme 
and  Surgery. 

“A  more  elegant  work  than  the  one  before  us  could  not  easily  be  placed  by  a physician  upon  the  table  of 
bis  student.” — Western  Journal  of  Medicine  and  Surgery. 

“We  were  much  pleased  with  Part  I,  but  the  Second  Part  gratifies  us  still  more,  both  as  regards  the  attract- 
ive nature  of  the  subject,  (The  Dermoid  and  Muscular  Systems.)  and  the  beautiful  artistical  execution  of  the 
d lustrations.  We  have  here  delineated  the  most  accurate  microscopic  views  of  some  of  the  tissues,  as,  for 
instance,  the  cellular  and  adipose  tissues,  the  epidermis,  rete  mucosum  and  cutis  vera,  the  sebaceous  and 
perspiratory  organs  of  the  skin,  the  perspiratory  glands  and  hairs  of  the  skin,  and  the  hair  and  nails.  Then 
follows  the  general  anatomy  of  the  muscles,  and,  lastly,  their  separate  delineations.  We  would  recommend 
this  Anatomical  Atlas  to  our  readers  in  the  very  strongest  terms.” — New  York  Journal  of  Medicine  and  Sur- 
gery. 


16 


LEA  & BLANCHARD’S  PUBLICATIONS. 


THERAPEUTICAL  LIBRARY. 


PEREIRA’S  MATERIA  MEDICA. 

WITH  NEARLY  THREE  HUNDRED  ENGRAVINGS  ON  WOOD. 

A NEW  EDITION,  LATELY  PUBLISHED. 


THE  ELEMENTS  OF 

MATERIA  MEDICA  AND  THERAPEUTICS. 

COMPREHENDING  THE  NATURAL  HISTORY,  PREPARATION,  PROPERTIES,  COMPO- 
SITION, EFFECTS  AND  USES  OF  MEDICINES. 

BY  JONATHAN  PEREIRA,  M.D.,  F.R.S.  and  L.S., 

Member  of  the  Society  of  Pharmacy  of  Paris;  Examiner  in  Materia  Metlica  and  Pharmacy  of  the  University 
of  London ; Lecturer  on  Materia  Medica  at  the  London  Hospital,  &c.  &.C. 

Second  American,  from  the  last  London  Edition,  enlarged  and  improved. 

WITH  NOTES  AND  ADDITIONS  BY  JOSEPH  CARSON,  M.D. 

In  Two  Volumes,  Octavo,  containing  Fifteen  Hundred  very  large  Pages,  illustrated  by 
Two  Hundred  and  Seventy-five  Wood-cuts. 

Part  I.  contains  the  General  Action  and  Classification  of  Medicines  and  the  Mineral  Materia 
Medica.  Part  II.,  the  Vegetable  and  Animal  Kingdoms,  including  diagrams  explanatory  of  the 
Processes  of  the  Pharmacopoeias,  a tabular  view  of  the  History  of  the  Materia  Medica,  from  the 
earliest  times  to  the  present  day,  with  the  Introduction  of  the  Processes  of  the  New  Edinburgh 
Pharmacopoeia,  and  a very  copious  index.  It  also  contains  additional  articles  on  Blental  Remedies, 
Light,  Heat,  Cold,  Electricity,  Magnetism,  Exercise,  Dietetics  and  Climate,  and  many  additional 
Wood-cuts,  illustrative  of  Pharmaceutical  Operations,  Crystallography,  Shape  and  Organization  of 
the  Feculas  of  Commerce,  and  the  Natural  History  of  the  Materia  Medica. 

In  passing  through  the  press  the  second  edition  of  this  standard  work,  the  opportunity  has  been 
taken  by  the  editor  to  correct  any  mistakes  or  inadvertencies  that  may  have  escaped  him  or  the 
author,  in  the  first  edition.  It  may  now  be  considered  as  entirely  worthy  of  the  confidence  of  the 
physician  and  pharmaceutist,  as  an  accurate  edition  of  the  most  complete  work  extant  on  the  subject. 

“An  Eneyelopcedia  of  knowledge  in  that  department  of  medical  science — by  the  common  consent  of  the  pro- 
fession the  most  elaborate  and  scientific  Treatise  on  Materia  Medica  in  our  language.” — Western  Journal  of 
Medicine  and  Surgery. 


THE  STUDENT’S  TEXT-BOOK  OF  MATERIA  MEDICA. 

NOW  AT  PRESS, 

A MANUAL  OF 

MATERIA  MEDICA  AND  THERAPEUTICS. 

By  J.  FORBES  ROYLE,  M.  D., 

PROFESSOR  IN  KING’S  COLLEGE,  LONDON. 

EDITED  BY 

J.  CARSON,  M.D., 

Professor  of  Materia  Medica  and  Pharmacy  in  the  Philadelphia  College  of  Pharmacy,  etc.  etc. 

In  One  Octavo  Volume,  with  Numerous  Splendid  Illustrations. 

This  work  will  contain  all  the  most  recent  information  and  investigations  in  the  various 
branches  connected  with  the  Materia  Medica,  and  under  the  supervision  of  its  able  editor, 
will  receive  whatever  alterations  and  additions  may  be  necessary  to  adapt  it  to  the  United 
Slates  Pharmacopoeia,  and  to  the  practice  of  this  country.  The  high  character  of  the  author 
will  attract  attention  to  the  work  as  a text-book  for  the  next  session  of  the  various  colleges, 
if  ready.  The  numerous  and  beautiful  illustrations  will  far  surpass  anything  that  has  as 
vet  been  attempted  in  this  way.  This  volume  will  be  brought  out  in  a style  to  match  Fer- 
guson’s Surgery,  Wilson’s  Anatomy,  &c.,  and  will  be  sold  at  a low  price. 


LEA  & BLANCHARD’S  PUBLICATIONS. 


17 


THE  GREAT  MEDICAL  LIBRARY. 

THE  CYCLOP/EDIA  OF  PRACTICAL  MEDICINE; 

COMPRISING  TREATISES  ON  THE 

NATURE  AND  TREATMENT  OF  DISEASES, 

MATERIA  MEDICA  & THERAPEUTICS, 

DISEASES  OF  WOMEN  AND  CHILDREN, 

MEDICAL  JURISPRUDENCE,  &c.  &c. 

EDITED  BY 

JOHN  FORBES,  M.  D.,  F.  R.  S., 
ALEXANDER  TWEED  IE,  M.D.,  F.R.S., 

AND 

JOHN  CONOLLY,  M.D. 

REVISED,  WITH  ADDITIONS, 

By  ROBLEY  DUNGLISON,  M.D. 

THIS  WORK  IS  NOW  COMPLETE,  AND  FORMS 

• FOUR  LARGE  SUPER-ROYAL,  OCTAVO  VOLUMES, 

CONTAINING  THIRTY-T WO . HUNDRED  AND  FIFTY-FOUR 
UNUSUALLY  LARGE  PAGES  IN  DOUBLE  COLUMNS, 

PRINTED  ON  GOOD  PAPER,  WITH  A NEW  AND  CLEAR  TYPE. 

THE  WHOLE  WELL  AND  STRONGLY  BOUND, 

WITH  RAISED  BANDS  AND  DOUBLE  TITLES. 

Or,  to  be  had  in  twenty-four  parts,  at  Fifty  Cents  each. 

For  a list  of  Articles  and  Authors , together  with  opinions  of  the  press,  see  Supplement  to  the  No- 
vember number  of  the  Medical  News  and  Library. 

This  work  having  been  completed  and  placed  before  the  profession,  has 
been  steadily  advancing  in  favor  with  all  classes  of  physicians.  The  nu- 
merous advantages  which  it  combines,  beyond  those  of  any  other  work  ; 
the  weight  which  each  article  carries  with  it,  as  being  the  production  of 
some  physician  of  acknowledged  reputation  who  has  devoted  himself 
especially  to  the  subject  confided  to  him,  the  great  diversity  of  topics 
treated  of ; the  compendiousness  with  which  everything  of  importance  is 
digested  into  a comparatively  small  space ; the  manner  in  which  it  has 
been  brought  up  to  the  day,  everything  necessary  to  the  American  prac- 
titioner having  been  added  by  Dr.  Dunglison  ; the  neatness  of  its  mecha- 
nical execution,  and  the  extremely  low  price  at  which  it  is  afforded, 
combine  to  render  it  one  of  the  most  attractive  works  now  before  the  pro- 
fession. As  a book  for  constant  and  reliable  reference,  it  presents  advan- 
tages which  are  shared  by  no  other  work  of  the  kind.  To  country  prac- 
titioners, especially,  it  is  absolutely  invaluable,  comprising  in  a mode- 
rate space,  and  trifling  cost,  the  matter  for  which  they  would  have  to 
accumulate  libraries,  when  removed  from  public  collections.  The  steady 
and  increasing  demand  with  which  it  has  been  favored  since  its  completion, 
shows  that  its  merits  have  been  appreciated,  and  that  it  is  now  universally 
considered  as  the 

LIBRARY  FOR  CONSULTATION  AND  REFERENCE. 


18 


LEA  & BLANCHARD’S  PUBLICATIONS. 


WORKS  BY  PROFESSORS  CHURCHILL,  MEIGS,  &c. 

CHURCHILL’S  MIDWIFERY. 

A New  Edition,  Just  Published. 


ON  THE  THEORY  AND  PRACTICE  OF  MIDWIFERY. 

BY  FLEETWOOD  CHURCHILL,  M.I).,  M.R.  I.  A., 

Licentiate  of  the  College  of  Physicians  in  Ireland;  Physician  to  the  Western  Lying-in  Hospital ; Lecturer  on 
Midwifery,  &e.,  in  the  Richmond  Hospital  Medical  School,  &c.  &c. 

WITH  NOTES  AND  ADDITIONS 

BY  ROBERT  M.  HUSTON,  M.D., 

Professor  of  Materia  Medica  and  General  Therapeutics,  and  formerly  of  Obstetrics  and  the  Diseases  of  Wo- 
men and  Children  in  the  Jefferson  Medical  College  of  Philadelphia;  President  of  the  Philadelphia 
Medical  Society,  &c.  &c. 

SECOND  AMERICAN  EDITION. 

WITH  ONE  HUNDRED  AND  TWENTY-EIGHT  ILLUSTRATIONS, 
ENGRAVED  BY  GILBERT  FROM  DRAWINGS  BY  BAGG  AND  OTHERS. 

In  One  beautiful  Octavo  Volume. 

The  call  for  a second  edition  of  Dr.  Churchill’s  Midwifery,  within  so  short  a time  after  the  ap- 
pearance of  the  first,  is  satisfactory  evidence  that  the  profession  in  this  country  appreciate  the  high 
value  of  the  work.  Both  as  a text-book  for  the  student  and  as  a manual  for  the  practitioner,  it  has 
a deservedly  great  reputation,  especially  for  the  fulness  and  clearness  with  which  the  physiological 
details  are  wrought  out  and  brought  to  illustrate  the  practical  part.  To  render  the  present  edition 
worthy  of  a continuance  of  the  favor  and  confidence  so  signally  manifested  towards  its  predecessor, 
the  editor  has  carefully  added  all  the  new  facts  and  observations  which  have  transpired  since  the 
publication  of  the  last  edition,  or  such  at  least  as  appeared  to  him  deserving  of  being  recorded. 
These  relate  to  some  of  the  most  important  points  in  physiology  and  obstetrical  practice.  Various 
new  illustrations  have  been  introduced,  and  the  whole  brought  up,  as  far  as  possible,  to  the  day  of 
publication. 


A NEW  EDITION  OF  CHURCHILL  ON  FEMALES. 

THE  DISEASES  OF  FEMALES, 

INCLUDING  THOSE  OF 

PREGNANCY  AND  CHILDBED. 

BY  FLEETWOOD  CHURCHILL,  M.D., 

Author  of  “ Theory  and  Practice  of  Midwifery,”  &c.  &c. 

THIRD  AMERICAN,  FROM  THE  SECOND  LONDON  EDITION,  WITH  ILLUSTRATIONS- 

EDITED,  WITH  NOTES, 

BY  ROBERT  M.  HUSTON,  M.  D.,  &c.  &c. 

In  One  Volume,  8vo. 

“ In  complying  with  the  demand  of  the  profession  in  this  country  for  a third  edition,  the  Editor 
has  much  pleasure  in  the  opportunity  thus  afforded  of  presenting  the  work  in  its  more  perfect  form. 
All  the  additional  references  and  illustrations  contained  in  the  English  copy  are  retained  in  this.” 

A TREATISE  ON  THE  DISEASES  OF  FEMALES, 

AND  ON  THE  SPECIAL  HYGIENE  OF  THEIR  SEX. 

WITH  NUMEROUS  WOOD-CUTS. 

BY  COLOMBAT  DE  L’ISERE,  M.  D., 

Chevalier  of  the  Legionof  Honor;  late  Surgeon  to  the  Hospital  of  the  Rue  de  Valois,  devoted  to  the  Diseases 

of  Females,  &c.  &c. 

TRANSLATED,  WITH  MANY  NOTES  AND  ADDITIONS, 

By  C.  D.  MEIGS,  M.D., 

Professor  of  Obstetrics  and  Diseases  of  Women  and  Children  in  the  Jefferson  Medical  College,  &c.  &c. 

In  One  Large  Volume,  8vo. 

“We  are  satisfied  it  is  destined  to  take  the  front  rank  in  this  department  of  medical  science;  it  is 
beyond  all  comparison,  the  most  learned  Treatise  on  the  Diseases  of  Females  that  has  ever  been 
written,  there  being  more  than  one  thousand  distinct  authorities  quoted  and  collected  by  the  inde- 
fatigable author.  It  is  in  fact  a complete  exposition  of  the  opinions  and  practical  methods  of  all 
the  celebrated  practitioners  of  ancient  and  modern  times.  The  Editor  and  Translator  has  per- 
formed his  part  in  a manner  hardly  to  be  surpassed.  The  translation  is  faithful  to  the  original,  and 
yet  elegant.  More  than  one  hundred  pages  of  original  matter  have  been  incorporated  in  the  text, 
constituting  a seventh  part  of  the  whole  volume.” — New  York  Journal  of  Medicine. 


LEA  & BLANCHARD’S  PUBLICATIONS. 


19 


WORKS  BY  PROFESSOR  W.  P.  DEWEES. 

MEW  EDITIONS. 

DEWEES’S^MIDWIFESY, 

A COMPREHENSIVE  SYSTEM  OF  MIDWIFERY. 

CHIEFLY  DESIGNED  TO  FACILITATE  THE  INQUIRIES  OF  THOSE  WHO  MAY  BE  PUR- 
SUING THIS  BRANCH  OF  STUDY. 

ILLUSTRATED  BY  OCCASIONAL  CASES  AND  MANY  ENGRAVINGS. 

Tenth  Edition,  with  the  Author's  last  Improvements  and  Corrections. 

BY  WILLIAM  P.  DEWEES,  M.  D., 

LATE  PROFESSOR  OF  MIDWIFERY  IN  THE  UNIVERSITY  OF  PENNSYLVANIA,  ETC. 

In  one  volume,  octavo. 

That  this  work,  notwithstanding  the  length  of  time  it  has  been  before  the  profession,  and  the 
numerous  treatises  that  have  appeared  since  it  was  written,  should  have  still  maintained  its  ground, 
and  passed  to  edition  after  edition,  is  sufficient  proof  that  in  it  the  great  practical  talents  of  the 
author  were  fully  placed  before  the  profession.  Of  the  book  itself  it  would  be  superfluous  to 
speak,  having  been  so  long  and  so  favorably  known  throughout  the  country  as  to  have  become 
identified  with  American  Obstetrical  Science. 


DEWEES  ON  FEMALES. 

A TREATISE  ON  THE  DISEASES  OE  FEMALES, 

BY  WILLIAM  P.  DEWEES,  M.  D.,  &c. 

LATE  PROFESSOR  OF  MIDWIFERY  IN  THE  UNIVERSITY  OF  PENNSYLVANIA,  ETC. 

EIGHTH  EDITION, 

With  the  Author’s  last  Improvements  and  Corrections. 

In  one  octavo  volume,  with  plates. 

D E W E E S ON  CHI L D R E N . 

A TREATISE  ON  THE 

PHYSICAL  AND  MEDICAL  TREATMENT  OF  CHILDREN, 

BY  WILLIAM  P.  DEWEES,  M.D., 

LATE  PROFESSOR  OF  MIDWIFERY  IN  THE  UNIVERSITY  OF  PENNSYLVANIA,  ETC.  ETC. 

EIGHTH  EDITION. 

In  one  volume,  octavo. 

This  edition  embodies  the  notes  and  additions  prepared  by  Dr.  Dewees  before  his  death,  and  will  be  found 
much  improved. 

The  objects  of  this  work  are,  1st,  to  teach  those  who  have  the  charge  of  children,  either  as  parent  or  guardian, 
the  most  approved  methods  of  securing  and  improving  their  physical  powers.  This  is  attempted  by  pointing 
out  the  duties  which  the  parent  or  the  guardian  owes  for  this  purpose,  to  this  interesting  but  helpless  class  of 
beings,  and  the  manner  by  which  their  duties  shall  be  fulfilled.  And  2d,  to  render  available  a long  experi- 
ence to  those  objects  of  our  affection  when  they  become  diseased.  In  attempting  this,  the  author  has  avoided 
as  much  as  possible,  “technicality,”  and  has  given,  if  he  does  not  flatter  himself  too  much,  to  each  disease  of 
which  he  treats,  its  appropriate  and  designating  characters,  with  a fidelity  that  will  prevent  any  two  being  con- 
founded together,  with  the  best  mode  of  treating  them,  that  either  his  own  experience  or  that  of  others  has 
suggested. 

Physicians  cannot  too  strongly  recommend  the  use  of  this  book  in  all  families. 

ASHWELL  ON  THETdISEASES  OF  FEMALES. 

A PRACTICAL  TREATISE  ON  THE 

DISEASES  PECULIAR  TO  WOMEN. 

ILLUSTRATED  BY  CASES 

DERIVED  FROM  HOSPITAL  AND  PRIVATE  PRACTICE. 

By  SAMUEL  ASHWELL,  M.  D., 

Member  of  the  Royal  College  of  Physicians ; Obstetric  Physician  and  Lecturer  to  Guy’s  Hospital,  &c. 

Edited  by  PAUL  BECK  GODDARD,  M.  D. 

The  whole  complete  in  one  large  octavo  volume. 

“ The  most  able,  and  certainly  the  most  standard  and  practical  work  on  female  diseases  that  we 
have  yet  seen.” — Medico-Chirurgical  Review. 


20 


LEA  & BLANCHARD’S  PUBLICATIONS. 


LATELY  PUBLISHED, 

A NEW  EDITION  OF 

WILSON’S  HUMAN  ANATOMY, 

MUCH  IMPROVED. 

A SYSTEM  OTTuITN  ANATOMY, 

GENERAL  AND  SPECIAL. 

BY  ERASMUS  WILSON,  M.D., 

LECTURER  ON  ANATOMY,  LONDON. 

SECOND  AMERICAN  EDITION,  EDITED  BY 

PAUL  B.  GODDARD,  A.M.,M.D., 

Professor  of  Anatomy  and  Histology  in  the  Franklin  Medical  College,  Philadelphia. 

WITH  OVER  TWO  HUNDRED  ILLUSTRATIONS. 

Beautifully  Printed  from  the  Second  London  Edition,  in  One  very  neat  Octavo  Volume. 

“ Mr.  Wilson,  before  the  publication  of  this  work,  was  very  favorably  known  to  the  profession  by  his  trea- 
tise on  Practical  and  Surgical  Anatomy;  and,  as  this  is  the  Second  American  Edition,  from  the  second  London 
Edition,  since  1840,  any  special  commendation  of  the  high  value  of  the  present  work,  on  our  part,  would  be 
supererogatory.  Besides,  the  work  has  been  translated  at  Berlin,  and  overtures  were  repeatedly  made  to  the 
London  publisher  for  its  reproduction  in  France.  The  work  is,  undoubtedly,  a complete  system  of  human 
anatomy,  brought  up  to  the  present  day.  The  illustrations  are  certainly  very  beautiful,  the  originals  having 
been  expressly  designed  and  executed  for  this  work  by  the  celebrated  Bagg  of  London;  and,  in  the  American 
edition  they  have  been  copied  in  a masterly  and  spirited  manner.  As  a text-book  in  the  various  colleges  we 
would  commend  it  in  the  highest  terms.” — New  York  Journal  of  Medicine. 


WILSON’S  DISSECTOR. 

THE  DISSECTOR; 

OR,  PRACTICAL  AND  SURGICAL  ANATOMY. 

BY  ERASMUS  WILSON, 

Author  of  “A  System  of  Human  Anatomy,  &c. 

WITH  ONE  HUNDRED  AND  SIN  ILLUSTRATIONS. 

MODIFIED  AND  RE-ARRANGED  BY 

PAUL  B.  GODDARD,  M.  D., 

Professor  of  Anatomy  and  Histology  in  the  Franklin  Medical  College,  Philadelphia. 

In  One  Large  Royal  Duodecimo  Volume,  Sheep. 

“ It  strikes  us  as  being  all  that  a “ Dissector”  should  be.  The  wood-cuts  are  numerous  and  will 
afford  the  student  the  most  essential  aid  in  the  dissecting  room.” — West.  Journ.  of  Med.  and  Surg. 


WILSON  ON  THE  SKIN. 

A PRACTICAL  AND  THEORETICAL  TREATISE 

ON  THE 

DIAGNOSIS,  PATHOLOGY  AND  TREATMENT 
OF  DISEASES  OF  THE  SKIN; 

ARRANGED  ACCORDING  TO  A NATURAL  SYSTEM  OF  CLASSIFICATION, 

AND  PRECEDED  BY 

AN  OUTLINE  OF  THE  ANATOMY  AND  PHYSIOLOGY  OF  THE  SKIN. 

BY  ERASMUS  WILSON, 

' Lecturer  on  Anatomy  and  Physiology  in  the  Middlesex  Hospital  Medical  School,  &c.  &c. 

In  One  Neat  Octavo  Volume,  Cloth. 

“ It  is  a sound  book  of  practice.  As  a practical  guide  to  the  classification,  diagnosis  and  treatment  of  the  dis 
eases  of  the  skin,  the  hook  is  complete.  We  know  nothing,  considered  in  this  aspect,  better  in  our  language ; 
it  is  a safe  authority  in  all  the  matters  which,  in  this  range  of  diseases,  engage  the  practitioner’s  attention,  and 
possesses  the  high  quality,  unknown,  we  believe,  to  every  older  manual,  of  being  on  a level  with  Science’s  high 
water  mark. — Medical  Times. 


LEA  & BLANCHARD’S  PUBLICATIONS. 


21 


A NEW  AND  COMPLETE  WORK  ON  FEVERS. 


FEYEES; 

THEIR  DIAGNOSIS,  PATHOLOGY  & TREATMENT. 

PREPARED  AND  EDITED  WITH  LARGE  ADDITIONS, 

FROM  THE  ESSAYS  ON  FEVER  IN 

TWEEDIE’S  LIBRARY  OF  PRACTICAL  MEDICINE, 

BY 

MEREDITH  CLYMER,  M.  D, 

Professor  of  the  Principles  and  Practice  of  Medicine  in  Franklin  Medical  College,  Philadelphia  ; 

Consulting  Physician  to  the  Philadelphia  Hospital ; Fellow  of  the  Col- 
lege of  Physicians,  fyc.  |c. 

In  one  octavo  volume  of  600  pages. 

The  want  of  a distinct  treatise  on  Fevers,  embodying  the  received  doctrines  of  their  pathology  and 
treatment  has  long  been  felt  and  generally  acknowledged.  To  supply  this  deficiency  in  medical 
literature  is  the  object  of  the  present  volume.  It  has  been  prepared  from  the  Essays  on  Fever 
contributed  by  Drs.  Christison,  Shapter,  Burrows,  Gregory  and  Locock,  to  Dr.  Tweedie’s  “ Library 
of  Practical  Medicine,”  and  will  be  found  to  embrace  the  whole  class  of 

Idiopathic  Fevers, — Continued,  Periodical,  Eruptive,  and  Puerperal, 

The  additions  of  the  Editor,  amounting  to  about  one-half  of  the  volume,  have  been  chiefly  made 
with  reference  to  the  Fevers  of  this  country.  It  has  been  his  aim  to  render  the  work  as  complete  as 
possible,  and  to  adapt  it  particularly  to  the  necessities  of  the  American  Practitioner. 


WILLIAMS’  PATHOLOGY. 

PRINCIPLES  OF  MEDICINE, 

COMPRISING 

GENERAL  PATHOLOGY  AND  THERAPEUTICS, 

AND  A GENERAL  VIEW  OF 

ETIOLOGY,  NOSOLOGY,  SEMEIOLOGY,  DIAGNOSIS  AND  PROGNOSIS. 

BY  CHARLES  J.  B.  WILLIAMS,  M.  D.,  F.  R.  S., 

Fellow  of  the  Royal  College  of  Physicians,  &c. 

WITH  NOTES  AND  ADDITIONS, 

BY  MEREDITH  CLYMER,  M.D.,&c. 

In  one  volume,  8uo. 


WILLIAMS  AND  CLYMER  ON  THE  CHEST,  & c 

A TREATISE  ON  THE 

DISEASES  OF  THE  RESPIRATORY  {ORGANS, 

INCLUDING 

THE  TRACHEA,  LARYNX,  LUNGS,  AND  PLEURA. 

BY  CHARLES  J.  B.  WILLIAMS,  M.D., 

Consulting  Physician  to  the  Hospital  for  Consumption  and  Diseases  of  the  Chest ; Author  of 
“Principles  of  Medicine,”  &c.  &c. 

" WITH  NUMEROUS  ADDITIONS  AND  NOTES, 

BY  MEREDITH  CLYMER,  M.D.,  &c. 

In  one  neat  octavo  volume,  with  cuts. 

This  work  recommends  itself  to  the  notice  of  the  profession  as  containing  a more  particular  and 
detailed  account  of  the  affections  of  which  it  treats  than  perhaps  any  other  volume  before  the  public. 

“The  wood-cuts  illustrating  the  physical  exmination  of  the  chest,  are  admirably  executed,  and  the  whole 
mechanical  execution  of  the  work  does  much  credit  to  the  publishers.  This  work  is  undoubtedly  destined  to 
take  precedence  of  all  others  yet  published  on  the  ‘ Respiratory  Organs,’  and  as  a text-book  for  teachers  and 
students,  no  better  in  the  present  state  of  the  science  is  to  be  expected/' — Ntu > York  Journal  of  Medicim. 


22 


LEA  & BLA  CHARD’S  PUBLICATIONS. 


KIRBY  & SPENCE’S  ENTOMOLOGY,  FOR  POPULAR  USE, 

AN  INTRODUCTION  TO  ENTOMOLOGY; 

OR,  ELEMENTS  OF  THE  NATURAL  HISTORY  OF  INSECTS  : COMPRISING 
AN  ACCOUNT  OF  NOXIOUS  AND  USEFUL  INSECTS,  OF  THEIR 
METAMORPHOSES,  FOOD,  STRATAGEMS,  HABITATIONS, 
SOCIETIES,  MOTIONS,  NOISES,  HYBERNATION, 

INSTINCT,  &c.,  &c. 

With  Plates.  Plain  or  Colored. 

By  WILLIAM  KIRBY,  M.A.,  F.R.S.  And  WILLIAM  SPENCE,  Esq.,  F.R.S. 

FROM  THE  SIXTH  LONDON  EDITION. 

Which  was  Corrected  and  Considerably  Enlarged, 

In  One  Large  Octavo  Volume , extra  cloth . 

This  work,  as  il  at  present  stands,  is  acknowledged  to  be  the  best  extant  as  a popular  introduction  to  the 
science,  containing  an  immense  amount  of  singular  and  interesting  information,  conveyed  in  a simple  and 
agreeable  manner.  In  preparing  the.  last  edition,  from  which  this  is  printed,  the  authors  have  omitted  the  two 
last  volumes,  as  being  too  scientific  for  popular  use,  and  arranged  it  as  it  now  is,  forming  a complete  exposi 
tiou  of  the  principles  of  the  study,  unincumbered  with  Anatomical  or  scientific  details. 

“We  are  well  aware  that  the  physician  engaged  in  an  engrossing  practice,  whether  in  town  or  country, 
has  not  much  leisure  for  the  perusal  of  books  unconnected  with  his  profession ; but  we  know  just  as  well,  that 
while  the  few  are  thus  immersed  in  business,  the  many  have  the  command  of  more  time  than  they  are  disposed 
to  give  to  professional  reading.  How  many  are  the  hours  wasted  by  nearly  every  young  physician,  waiting 
for  practice — anxious,  dreary  hours,  because  unoccupied  ! Why  not  spend  these  hours  in  the  study  of  such 
works  as  that  of  Kirby  & Spence,  wherein  the  physiologist,  farmer,  horticulturist,  philosopher,  and  moralist, 
may  find  matter  to  instruct  him. — The  Western  Journal  of  Medicine  and  Surgery. 

“The  republication  of  this  work,  which  has  for  many  years  enjoyed  a very  high  and  constantly  increasing 
popularity  in  Great  Britain,  confers  a decided  benefit  upon  natural  science  in  this  country.  It  is  a free,  careful 
and  authentic  exposition  of  the  very  extensive  department  of  study,  of  which  it  treats,  and  has  done  much 
abroad  to  attract  attention  to  a branch  which,  until  its  publication,  has  found  comparatively  little  favor  with  the 
scientific  students  of  Great  Britain.  The  treatise  of  Messrs.  Kirby  & Spence  is  well  adapted,  not  only  by  its 
intrinsic  merit,  but  by  its  attractive  style,  to  introduce  the  subject  to  popular  favor.  It  is  thrown  into  the  form 
of  letters,  and  although  abounding  to  some  extent  in  scientific  terms,  it  is  divested  of  technicality  so  far  as  pos- 
sible, and  by  a very  agreeable  intermixture  of  anecdotes.  &c..  is  made  a pleasant  and  entertaining,  as  well  as 
very  instructive  and  important  work.  It  is  now  reprinted  from  the  sixth  London  edition,  which  has  been 
revised  and  corrected,  and  forms  a very  handsome  octavo  volume  of  about  GOO  pages.  Those  who  have  never 
given  any  attention  to  the  subject  of  which  it  treats,  will  find  embodied  in  it  an  immense  amount  of  very  inte- 
resting and  useful  information,  set  forth  in  an  agreeable  and  attractive  style.” — N.  Y.  Courier  and  Enquirer. 


THE  CHEMISTRY 

OF  THE 

FOUR  SEASONS, 

BY  THOMAS  GRIFFITH, 

Lecturer  on  Chemistry  at  St.  Bartholomew’s  Hospital,  &c.  &c. 

IN  ONE  VERY  NEAT  DUODECIMO  VOLUME. 

With  Numerous  Wood- cuts.  A New  Work. 

The  object  of  this  little  book  is  to  show  in  a popular  and  agreeable  manner  the  chemical  agency 
exerted  in  the  various  phenomena  of  nature.  It  forms  a neat  volume  for  the  Centre  Table. 


A TEXT  BOOK  OF 

PRACTICAL  GEOLOGY  AND  MINERALOGY. 

WITH  INSTRUCTIONS  FOR  THE  QUALITATIVE  ANALYSIS  OF  MINERALS, 

BY  JOSHUA  TRIMMER,  F.  G.  S. 

WITH  TWO  HUNDRED  AND  TWELVE  WOOD-CUTS. 

A handsome  octavo  volume,  bound  in  embossed  cloth. 

This  is  a systematic  introduction  to  Mineralogy,  and  Geology,  admirably  calculated  to  instruct  the  student  in 
those  sciences.  The  organic  remains  of  the  various  formations  are  well  illustrated  by  numerous  hgures,  which 
are  drawn  with  great  accuracy. 


LEA  & BLANCHARD’S  PUBLICATIONS. 


23 


GRAHAM’S  CHEMISTRY., 

THE  ELEMENTS  OF  CHEMISTRY. 

INCLUDING  THE  APPLICATION  OF  THE  SCIENCE  TO  THE  ARTS. 

With  Numerous  Illustrations. 

BY  THOMAS  GRAHAM,  F.  R.  S.  L.  and  E.  D. 

Professor  of  Chemistry  in  University  College.  London,  &c.  &e. 

WITH  NOTES  AND  ADDITIONS, 

BY  ROBERT  BRIDGES,  M.D.,  &c.  &c, 

In  One  Volume  Octavo. 

The  great  advancement  recently  made  in  all  branches  of  chemical  investigation,  renders  neces- 
sary an  enlarged  work  which  shall  clearly  elucidate  the  numerous  discoveries,  especially  in  the 
department  connected  with  organic  Chemistry  and  Physiology,  in  which  such  gigantic  strides 
have  been  made  during  the  last  few  years.  The  present  treatise  is  considered  by  eminent  judges 
to  fulfil  these  indications,  and  to  be  peculiarly  adapted  to  the  necessities  of  the  advanced  medical 
student  and  practitioner.  In  adapting  it  to  the  wants  of  the  American  profession,  the  editor  has 
endeavored  to  render  his  portion  of  the  work  worthy  the  exalted  reputation  of  the  first  chemist  ot 
England.  It  is  already  introduced  in  many  of  the  Colleges,  and  has  universal  approbation. 

FOWNES’S  CHEMISTRY  FOR  STUDENTS. 

ELEMENTARY  CHEMISTRY, 

THEORETICAL  AND  PRACTICAL. 

By  GEORGE  FOWNES,  Ph.  D., 

Chemical  Lecturer  in  the  Middlesex  Hospital  Medical  School,  &c.  &c. 

With  Numerous  Illustrations.  Edited,  with  Additions, 

By  ROBERT  BRIDGES,  M.  D., 

Professor  of  General  and  Pharmaceutical  Chemistry  in  the  Philadelphia  College  ol  Pharmacy,  &c.  &c. 

In  one  large  duodecimo  volume,  sheep  or  extra  cloth. 

The  character  of  this  work  is  such  as  to  recommend  it  to  all  colleges  in  want  of  an  elementary 
text-book,  and  to  all  practitioners  who  wish  to  place  a compendious  manual  in  the  hands  of  their 
students.  It  is  fully  brought  up  to  the  day,  containing  all  the  late  views  and  discoveries  that  have 
so  entirely  changed  the  face  of  the  science,  and  it  is  completely  illustrated  with  very  numerous 
wood  engravings  explanatory  of  all  the  different  processes  and  forms  of  apparatus.  Though  strictly 
scientific,  it  is  written  with  great  clearness  and  simplicity  of  style,  rendering  it  easy  to  be  mastered 
by  those  commencing  the  study.  The  low  price  at  which  it  is  sold,  places  it  within  the  reach  of  all. 

Though  this  work  has  been  so  recently  published,  it  has  already  been  adopted  as  a text-book  by 
many  of  the  Medical  Institutions  throughout  the  country.  As  a work  for  the  first  class  student,  and 
as  an  introduction  to  the  larger  systems  of  Chemistry,  such  as  Graham’s,  there  has  been  but  one 
opinion  expressed  concerning  it,  and  it  may  now  be  considered  as 

THE  TEXT-BOOK  EOR  THE  CHEMICAL  STUDENT. 

SIMON’S  CHEMISTRY  OF  MAN. 

ANIMAL  CHEMISTRY. 

WITH  REFERENCE  TO  THE  PHYSIOLOGY  & PATHOLOGY  OF  MAN. 

BY  DR.  J.  FRANZ  SIMON. 

TRANSLATED  AND  EDITED  BY 
GEORGE  E.  DAY,  M.  A.  & L.  M.  Cantab.,  &c. 

With  plates.  In  one  octavo  volume , of  over  seven  hundred  pages,  sheep,  or  in  two  parts,  boards . 

This  important  work  is  now  complete  and  may  be  had  in  one  large  octavo  volume.  Those  who 
obtained  the  first  part  can  procure  the  second  separate. 

“ No  treatise  on  physiological  chemistry  approaches,  in  fulness  and  accuracy  of  detail,  the  work  which 
stands  at  the  head  of  this  article.  It  is  the  production  of  a man  of  true  German  assiduity,  who  has  added  to  his 
own  researches  the  results  of  the  labors  of  nearly  every  other  inquirer  in  this  interesting  branch  of  science. — 
The  death  of  such  a laborer,  which  is  mentioned  in  the  preface  to  the  work  as  having  occurred  prematurely  in 
1S42,  is  indeed  a calamity  to  science.  He  had  hardly  reached  the  middle  term  of  life,  and  yet  had  made  himself 
known  all  over  Europe,  and  in  our  country,  where  his  name  has  been  familiar  for  several  years  as  amon»  the 

most  successful  of  the  cultivators  of  the  Chemistry  of  Man It  is  a vast  repository  of  facts,  to  which  the 

teacher  aud  student  may  refer  with  equal  satisfaction.”—  The  Western  Journal  of  Medicine  and  Surgery, 


:4 


LEA  «Si  BLANCHARD’S  PUBLICATIONS. 


WATSON’S  PRACTICE  OF  PHYSIC. 

New  Edition  by  Condie. 

LECTURES  ON  THE 

PRINCIPLES  AND  PRACTICE  OF  PHYSIC. 

DELIVERED  AT  KING’S  COLLEGE,  LONDON. 

BY  THOMAS  WATSON,  M.  D.,  &c.  &c. 

Second  American,  from  the  Second  London  Edition, 

REVISED,  WITH  ADDITIONS, 

BY  D.  FRANCIS  CONDIE,  M.  D., 

Author  of  a work  on  the  “ Diseases  of  Children,”  &c. 

In  one  Octavo  Volume, 

Of  nearly  ELEVEN  HUNDRED  Large  Pages,  strongly  bound  with  raised  bands. 

c<  We  know  of  no  work  better  calculated  for  being  placed  in  the  hands  of  the  student,  and  for  a 
text-book,  and  as  such  we  are  sure  it  will  be  very  extensively  adopted.  On  every  important  point 
tiie  author  seems  to  have  posted  up  his  knowledge  to  the  day.” — American  Medical  Journal. 

The  rapid  sale  of  the  first  edition  of  this  work  is  an  evidence  of  its  merits,  and  of  its  general 
favor  with  the  American  practitioner.  To  commend  it  still  more  strongly  to  the  profession,  the 
publishers  have  gone  to  a great  expense  in  preparing  this  edition  with  larger  type,  finer  paper,  and 
stronger  binding,  with  raised  bands.  It  is  edited  with  reference  particularly  to  American  practice, 
by  Dr.  Condie;  and  with  these  numerous  improvements,  the  price  is  still  kept  so  low  as  to  be  within 
the  reach  of  all,  and  to  render  it  among  the  cheapest  works  offered  to  the  profession.  It  has  been 
received  with  the  utmost  favor  by  the  medical  press,  both  of  this  country  and  of  England,  a few  of 
the  notices  of  which,  together  with  a letter  from  Professor  Chapman,  will  be  found  in  the  Supple- 
ment to  The  Medical  News  and  Library,  for  November,  1845. 


A NEW  AND  IMPROVED  EDITION  OF 

RAMSBOTHAM’S  STANDARD  WORK  ON  PARTURITION. 

THE  PRINCIPLES  AND  PRACTICE  OF 

OBSTETRIC  MEDICINE  AND  SURGERY, 

IN  REFERENCE  TO 

THE  PROCESS  OF  PARTURITION. 

ILLUSTRATED  BY 

One  hundred  and  forty-eight  Large  Figures  on  55  Lithographic  Plates, 

BY  FRANCIS  H.  RAMSBOTHAM,  M.  D.,  &c. 

A NEW  EDITION,  FROM  THE  ENLARGED  AND  REVISED  LONDON  EDITION. 

In  one  large  imperial  octavo  volume,  well  bound. 

The  present  edition  of  this  standard  work  will  be  found  to  contain  numerous  and  important  improvements 
over  the  last.  Besides  much  additional  matter,  there  are  several  more  plates  and  wood-cuts,  and  those  which 
were  before  used  have  been  re-drawn.  This  book  has  long  been  known  to  the  profession,  by  whom  it  has 
been  most  flatteringly  received.  A more  extended  advertisement,  with  a recommendatory  letterfrom  Professor 
.Hodge  of  the  University  of  Pennsylvania,  may  be  seen  in  the  November  Supplement  to  The  Medical  News. 

CONDIE  ON  CHILDREN. 

A PRACTICAL  TREATISE  ON 

THE  DISEASES  OF  CHILDREN, 

BY  D.  FRANCIS  CONDIE,  M.  D., 

Fellow  of  the  College  of  Physicians;  Member  of  the  American  Philosophical  Society,  &c.  See. 

IN  ONE  VOLUME,  OCTAVO. 

fry*  The  Publishers  would  particularly  call  the  attention  of  the  Profession  to  an  examination  of  this  work. 

“Dr.  Condie,  from  the  very  great  labor  which  he  has  evidently  bestowed  upon  this  book,  is  entitled  to  our 
respect  as  an  indefatigable  and  conscientious  student;  but  if  we  consider  the  results  of  his  labor,  we  cannot 
but  admit  his  claim  to  a place  in  the  very  first  rank  of  eminent  writers  on  the  practice  of  medicine.  Regard- 
ing his  treatise  as  a whole,  it  is  more  complete  and  accurate  in  its  descriptions,  while  it  is  more  copious  and 
more  judicious  in  its  therapeutical  precepts  than  any  of  Us  predecessors,  and  we  feel  persuaded  that  the  Ame- 
rican medical  profession  will  very  soon  regard  it,  not  only  as  a very  good,  but  as  the  very  best  ‘ Practica 
Treatise  on  the  Diseases  of  Children.’  ” — Am.  Med.  Journal. 


LEA  & BLANCHARD’S-  PUBLICATIONS. 


25 


THE  SURGICAL  WORKS  OF  SIR  ASTLEY  COOPER, 

LEA  & BLANCHARD  have  how  completed  the  last  volume  of  the  illustrated  works  of  Sir  Astley  Cooper. 
They  form  an  elegant  series;  the  works  on  Hernia,  the  Testis,  the  Thymus  Gland  and  the  Breast,  being  printed, 
illustrated  and  hound  to  match,  in  imperial  octavo  with  numerous  LITHOGRAPHIC  PLATES,  while  the 
Treatise  on  Dislocations  is  in  a neat  medium  octavo  form,  with  NUMEROUS  WOOD  CUTS  similar  to  the 
last  London  edition. 


SIR  ASTLEY  COOPER  ON  HERNIA, 

With  One  Hundred  and  Thirty  Fig  ures  in  Lithography. 

THE  ANATOMY  AND  SURGICAL  TREATMENT  OF 

ABDOMINAL  HERNIA. 

By  Sir  ASTLEY  COOPER,  Bart. 

Edited  by  C.  Aston  Key,  Surgeon  to  Guy’s  Hospital,  &c. 

This  important  work  of  Sir  Astley  is  printed  from  the  authorized  second  edition,  published  in  London,  in  large 
snper-royal  folio,  and  edited  by  his  nephew.  Professor  Key.  It  contains  all  the  Plates  and  all  the  Letterpress — 
there  are  no  omissions,  interpolations,  or  modifications — it  is  the  complete  work  in 
One  Large  Imperial  Octavo  Volume. 

With  over  130  Figures  on  26  Plates,  and  over  400  Large  Pages  of  Letterpress. 

The  correctness  of  the  Plates  is  guaranteed  by  a revision  and  close  examination  under  the  eye  of  a distin- 
guished Surgeun  of  this  city. 


ANOTHER  VOLUME  OF  THE  SERIES  CONTAINS  HIS  TREATISE 

ON  THE  STRUCTURE  AND  DISEASES  OF  THE  TESTIS. 

Illustrated  by  U0  Figures.  From  the  Second  London  Edition. 

BY  BRANSBY  B.  COOPER,  ESQ. 

AND  ALSO  ON  THE  ANATOMY  OF  THE  THYMUS  GLAND. 

Illustrated  by  51  Figures . 

The  two  works  together  in  one  beautiful  imperial  octavo  volume,  illustrated  with  twenty-nine  plates  in  the 
best  style  of  lithography,  and  printed  and  bound  to  match. 

The  Series  is  concluded  by 

COOPER  ON  THE 

ANATOMY  AND  DISEASES  OF  THE  BREAST,  &>., 

This  large  and  beautiful  volume  contains  THE  ANATOMY  OF  THE  BREAST: 
THE  COMPARATIVE  ANATOMY  OF  THE  MAMMARY  GLANDS: 
ILLUSTRATIONS  OF  THE  DISEASES  OF  THE  BREAST; 

And  Twenty-five  Miscellaneous  Surgical  Papers,  now  first  published  in  a collected  form. 
Br  Sir  ASTLEY  COOPER,  Bart.,  F.  R.  S.,  &c. 

The  whole  in  one  large  imperial  octavo  volume,  illustrated  with  two  hundred  and  fifty-two  figures  on 
thirty  six  Lithographic  Plates  ; well  and  strongly  bound. 


COOPER  ON  FRACTURES  AND  DISLOCATIONS, 

WITH  NUMEROUS  WOOD-CUTS. 

A TREATISE  ON  DISLOCATIONS  AND  FRACTURES  OF  THE  JOINTS. 

By  Sir  ASTLEY  COOPER,  Bart.,  F.  R.  S.,  Sergeant  Surgeon  to  the  King,  &c. 

A NEW  EDITION  MUCH  ENLARGED  ; 

Edited  by  BRANSBY  COOPER,  F.  R.  S.,  Surgeon  to  Guy’s  Hospital. 

WITH  ADDITIONAL  OBSERVATIONS  FROM 

Professor  JOHN  C.  WARREN,  of  Boston. 

With  numerous  engravings  on  wood , after  desig?is  by  Bagg , a memoir  and  a splendid  portrait  of  Sir 

Astley.  In  one  octavo  volume. 

The  peculiar  value  of  this,  as  of  all  of  Sir  Astley  Cooper’s  works,  consists  in  its  eminently  practical  charac- 
ter. His  nephew,  Bransby  B.  Cooper,  from  his  own  experience,  has  added  a number  of  cases.  Besides  this, 
Sir  Astley  lefi  behind  him  very  considerable  additions  in  MS.  for  the  express  purpose  of  being  introduced  into 
this  edition.  The  volume  is  embellished  with  ONE  HUNDRED  AND  THIRTY-THREE  WOOD-CUTS, 
and  contains  the  history  of  no  less  than  three  hundred  and  sixty-one  cases,  thus  embodying  the  records  of  a 
life  of  practice  of  the  Author  and  his  various  editors.  There  are  also  additional  Observations  from  notes  fur- 
nished by  John  C.  Warren,  M.  D.,  the  Professor  of  Anatomy  and  Surgery  in  Harvard  University. 

“ After  the  fiat  of  the  profession,  ii  would  be  absurd  in  us  to  eulogize  Sir  Astley  Cooper’s  Work  on  Fracturea 
and  Dislocations.  It  is  a national  one,  and  will  probably  subsist  as  long  as  English  Surgery,” — Medico-Chi- 
rurgical  Review. 


26 


LEA  & BLANCHARD’S  PUBLICATIONS. 


A NEW  MEDICAL  DICTIONARY, 

In  one  Volume,  large  12mo.,  now  ready,  at  a low  price, 

A DICTIONARY  OF 

THE  TERMS  USED  IN  MEDICINE 

AND 

THE  COLLATERAL  SCIENCES; 

By  RICHARD  D.  HOBLYN,  A.M.,  Oxon. 

FIRST  AMERICAN,  FROM  THE  SECOND  LONDON  EDITION. 

REVISED,  WITH  NUMEROUS  ADDITIONS, 

By  ISAAC  HAYS,  M.  D., 

Editor  of  the  American  Journal  of  the  Medical  Sciences. 

Believing  that  a work  of  this  kind  would  be  useful  to  the  profession  in  this  country,  the  publishers 
have  issued  an  edition  in  a neat  form  for  the  office  table,  at  a low  price.  Its  object  is  to  serve  as 
an  introduction  to  the  larger  and  more  elaborate  Dictionaries,  and  to  assist  the  student  commencing 
the  study  of  Medicine,  by  presenting  in  a concise  form  an  explanation  of  the  terms  most  used  in 
Medicine  and  the  Collateral  Sciences,  by  giving  the  etymology  and  definition  in  a manner  as  simple 
and  clear  as  possible,  without  going  into  details  ; and  bringing  up  the  work  to  the  present  time  by 
including  the  numerous  terms  lately  introduced.  This  design  the  author  has  so  ably  executed  as 
to  elicit  the  highest  encomiums  of  the  medical  press. 

It  has  been  edited  with  especial  reference  to  the  wants  of  the  American  practitioner,  the  native 
medicinal  plants  being  introduced,  with  the  formulae  for  the  various  officinal  preparations  : and  the 
whole  being  made  to  conform  to  the  Pharmacopoeia  of  the  United  States.  It  is  now  ready  in  one 
neat  royal  duodecimo  volume  of  four  hundred  pages  in  double  columns. 


TAYLOR’S  MEDICAL  JURISPRUDENCE. 

MEDICAL  JURISPRUDENCE. 

By  ALFRED  S.  TAYLOR, 

Lecturer  on  Medical  Jurisprudence  and  ChemiBtry  at  Guy’s  Hospital,  &c. 

With  Numerous  Notes  and  Additions,  and  references  to  American  Practice  and  Law. 

Br  R.  E.  GRIFFITH,  M.  D. 

In  one  volume,  8vo. 

“ We  recommend  Mr.  Taylor’s  work  as  the  ablest,  most  comprehensive,  and,  above  all,  the  most  practically 
"Useful  book  which  exists  on  the  subject  of  legal  medicine.  Any  man  of  sound  judgment,  who  has  mastered 
the  contents  of  Taylor’s  1 Medical  Jurisprudence,’  may  go  into  a court  of  law  with  the  most  perfect  confidence 
of  being  able  to  acquit  himself  creditably.” — Medico-Chirurgical  Review. 

“ As  we  expected,  it  has  become  truly  the  manual  of  both  the  medical  and  legal  professions, 
and  is  regarded  by  all  as  the  standard  authority  on  the  subject;  the  author,  also,  as  we  find  from 
the  public  prints,  is  the  person  consulted,  almost  as  a matter  of  course,  in  the  more  difficult  medico- 
legal cases. — The  British  and  Foreign  Medical  Review. 


LAWRENCE  ON  THE  EYE.  New  Edition— Now  Ready. 

A TREATISE  ON  THE  DISEASES  OF  THE  EYE. 

BY  W.  LAWRENCE,  F,  R.  8., 

Surgeon  Extraordinary  to  the  Queen,  Surgeon  to  St.  Bartholomew’s  Hospital,  & c.  &c. 

SECOND  AMERICAN,  FROM  THE  LAST  LONDON  EDITION, 

With  many  Modifications  and  Additions,  and  the  Introduction  of  over  one  hundred  Illustrations, 

BY  ISAAC  HAYS,  M.  D., 

Surgeon  to  Will’s  Hospital,  Physician  to  the  Philadelphia  Orphan  Asylum,  See.  Sec. 

IN  ONE  LARGE  OCTAVO  VOLUME. 

The  character  of  this  work  is  too  well  known  to  require  a word  of  commendation.  It  is  justly  considered  the 
best  we  possess  on  the  subject.  In  this  edition  will  be  found  many  important  alterations  and  improvements, 
bringing  the  work  up  to  the  level  of  the  present  state  of  knowledge  on  the  subjects  of  Ophthalmic  Surgery  and 
Practice.  The  chapters  on  the  Anatomy  and  Physiology  of  the  Organ  have  received  especial  augmentations; 
and  many  new  cuts  have  been  introduced,  rendering  the  whole  clear  and  comprehensible. 


LEA  & BLANCHARD’S  PUBLICATIONS. 


27 


MILLER’S  SURGICAL  WORKS. 

THE  PRINCIPLES  OF  SURGERY. 

BY  JAMES  MILLER,  F.  R.  S.E.,  F.R.  C.S.  E., 

Professor  of  Surgery  in  the  University  of  Edinburgh,  &c. 

In  one  neat  octavo  volume,  to  match  the  Author's  volume  on  “ Practice .” 

“ No  one  can  peruse  this  work  without  the  conviction  that  he  has  been  addressed  by  an  accom- 
plished surgeon,  endowed  with  no  mean  literary  skill  or  doubtful  good  sense,  and  who  knows  how 
to  grace  or  illumine  his  subjects  with  the  later  lights  of  our  rapidly  advancing  physiology.  The 
book  deserves  a strong  recommendation,  and  must  secure  itself  a general  perusal.” — Medical  Times. 

“ We  feel  no  hesitation  in  expressing  our  opinion  that  it  presents  the  philosophy  of  the  science 
more  fully  and  clearly  than  any  other  work  in  the  language  with  which  we  are  acquainted.” — Phi- 
ladelphia Medical  Examiner. 

“ To  the  student  who  wishes  to  acquire  a useful  practical  knowledge  of  the  pathology  of  sur- 
gical diseases,  it  is  impossible  to  recommend  abetter  guide  than  the  present  treatise  by  Mr.  Mil- 
ler.”— Edinburgh  Medical  and  Surgical  Journal. 

“ An  admirable  epitome  of  the  surgical  science  of  the  day.  Being  written  by  a sound  practical 
surgeon  accustomed  to  the  public  teaching  of  his  science,  it  has  the  clearness  of  diction  and  ar- 
rangement which  renders  it  an  excellent  manual  for  the  students  as  well  as  that  amount  of  scien- 
tific and  practical  information  which  makes  it  a safe  and  valuable  guide  to  the  practitioner.” — The 
Lancet. 


JUST  PUBLISHED. 

THE  PRACTICE  OF  SURGERY. 

BY  JAMES  MILLER. 

Professor  of  Surgery  in  the  University  of  Edinburgh. 

In  one  neat  octavo  volume. 

This  work  is  printed  and  bound  to  match  the  “ Principles  of  Surgery,”  by  Professor  Miller,'lately 
issued  by  L.  & B.  Either  volume  may  be  had  separately. 

“ This  work,  with  the  preceding  one,  forms  a complete  text-book  of  surgery,  and  has  been  under- 
taken by  the  author  at  the  request  of  his  pupils.  Although,  as  we  are  modestly  informed  in  the 
preface,  it  is  not  put  forth  in  rivalry  of  the  excellent  works  on  practical  surgery  which  already  exist, 
we  think  we  may  take  upon  ourselves  to  say,  that  it  will  form  a very  successful  and  formidable 
rival  to  most  of  them.  While  it  does  not  offer  the  same  attractive  illustrations,  with  which  some  of 
our  recent  text-books  have  been  embellished,  and  while  it  will  not,  as  indeed  is  not  its  design,  set 
aside  the  more  complete  and  elaborate  works  of  reference  which  the  profession  is  in  possession  of, 
we  have  no  hesitation  in  stating  that  the  two  volumes  form,  together,  a more  complete  text-book 
of  surgery  than  any  one  that  has  been  heretofore  offered  to  the  student.” — The  Northern  Journal 
qf  Medicine. 

“ Mr.  Miller  is  already  known  in  his  profession  as  an  able  writer  and  a well  informed  surgeon, 
and  the  book  before  us  is  calculated  to  maintain  his  reputation.  We  recommend  it  to  those  who 
want  a sound  guide,  or  wish  to  refresh  their  recollections.  The  characteristics  which  especially 
distinguish  the  work  are,  its  plain  good  sense,  or  the  selection  of  the  important  from  the  unimport- 
ant announcements  in  surgery  ; the  sound  indications  of  the  judgment  to  be  exercised  in  the  treat- 
ment of  surgical  diseases.” — The  Lancet. 

A NEW  AND  IMPROVED  EDITION  OF 

FERGUSSON’S  OPERATIVE  SURGERY. 

A SYSTEM  OF  PRACTICAL  SURGERY, 

BY  WILLIAM  FERGUSSON,  F.R.  S.E. 

SECOND  AMERICAN  EDITION,  REVISED  AND  IMPROVED. 

With  Two  Hundred  and  Fifty-two  Illustrations  from  Drawings  by  Bagg,  Engraved  by  Gilbert, 
With  Notes  and  Additional  Illustrations, 

BY  GEORGE  W.  NORRIS,  M.  D,,  &c. 

In  one  beautiful  octavo  volume  of  six  hundred  and  forty  large  pages. 

• 11  If  we  weTe  to  say  that  this  volume  by  Mr.  Fergusson,  is  one  excellently  adapted  to  the  student,  and  the  yet 
inexperienced  practitioner  of  surgery,  we  should  restrict  unduly  its  range.  It  isofthe  kind  which  every  medi- 
cal man  ought  to  have  by  him  for  ready  reference,  as  a guide  to  the  prompt  treatment  of  many  accidents  and 
injuries,  which  whilst  he  hesitates,  may  be  followed  by  incurable  defects,  and  deformities  of  structure,  if  not  by 
death  itself.  In  drawing  to  a close  our  notice  of  Mr.  Fergusson’s  Practical  Surgery,  we  cannot  refrain  from 
again  adverting  to  the  numerous  and  beautiful  illustrations  by  wood-cuts,  which  contribute  so  admirably  to 
elucidate  the  descriptions  in  the  text.  Dr.  Norris  has,  as  usual,  acquitted  himself  judiciously  in  his  office  of 
annotator.  His  additions  are  strictly  practical  and  to  the  point.”— Bulletin  of  Medical  Science. 


2$ 


LEA  & BLANCHARD’S  PUBLICATIONS, 


LIBRARY  OF  SURGERY. 


CHELIUS’S  SYSTEM  OF  SURGERY. 


A SYSTEM  OF  SURGERY. 

By  J.  M.  CHELIUS, 

Doctor  in  Medicine  and  Surgery,  Public  Professor  of  General  and  Ophthalmic  Surgery,  etc.  etc.  in  the 

University  of  Heidelberg. 

TRANSLATED  FROM  THE  GERMAN, 

AND  ACCOMPANIED  WITH  ADDITIONAL  NOTES  AND  OBSERVATIONS, 

By  JOHN  F.  SOUTH, 

SURGEON  TO  ST.  THOMAS'S  HOSPITAL. 

EDITED,  WITH  REFERENCE  TO  AMERICAN  AUTHORITIES, 

By  GEORGE  W.  NORRIS;  M.D. 

Publishing  in  Numbers,  at  Fifty  Cents  each. 

Nine  Numbers  are  now  ready:  and  the  whole  is  expected  to  be  complete  by  September  next,  forming 

Three  Large  Octavo  Volumes. 

That  this  work  should  have  passed  to  six  editions  in  Germany,  and  have  been  translated  into  no  less  than 
seven  languages,  is  sufficient  proof  of  its  value.  It  contains  what  is,  perhaps,  embraced  to  an  equal  extent 
by  no  other  work  on  the  subject  now  before  the  public— a complete  System  of  Surgery,  both  in  its  principles 
and  practice.  The  additions  of  the  translator,  Mr.  South,  are  very  numerous,  bringing  the  work  up  to  the  very 
day  of  publication,  and  embodying  whatever  may  have  been  omitted  by  the  author  respecting  English  Sur- 
gery; while  Dr.  Norris  will  take  equal  care  in  representing  the  state  of  the  Science  in  America. 

“Judging  from  a single  number  only  of  this  work,  we  have  no  hesitation  in  saying  that,  if  the  remaining  por- 
tions correspond  at  all  with  the  first,  it  will  be  by  far  the  most  complete  and  scientific  System  of  Surgery  in  the 
English  language.  We  have,  indeed,  seen  no  work  which  so  nearly  comes  up  to  our  idea  of  what  such  a pro- 
duction should  be,  both  as  a practical  guide  and  as  a work  of  reference,  as  this;  and  the  fact  that  it  has  passed 
through  six  editions  in  Germany,  and  been  translated  into  seven  languages,  is  sufficiently  convincing  proof  of 
its  value.  It  is  methodical  and  concise,  clear  and  accurate;  omitting  all  minor  details  and  fruitless  speculations, 
it  gives  us  all  the  information  we  want  in  the  shortest  and  simplest  form  The  New  York  Journal  of  Medicine. 

“The  scope  of  Professor  Chelius’s  Manual  is  indicated  by  its  title:  it  professes  to  treat,  systematically,  of  the 
science  and  art  of  Surgery,  but  within  such  compass  as  to  render  the  work  an  appropriate  introduction  and 
companion  to  his  lectures.  The  care,  however,  which  has  been  bestowed  upon  its  construction,  and  the  labor 
which  its  research  evinces,  would  be  ill  repaid  were  it  confined  to  this  sphere;  and  we  may  conscientiously 
say,  that  we  know  of  no  Manual  of  Surgery,  on  the  whole,  more  deserving  of  public  confidence,  or  more  vali> 
able  as  a guide  and  refresher  to  the  young  practitioner.  It  is  not  our  intention  at  present  critically  to  analyze 
Mr.  South’s  labors;  but  we  should  be  guilty  of  an  injustice  to  him  and  to  our  readers  if  we  did  not  cordially 
recommend  his  work  as  having  fair  promise  of  forming,  what  it  is  the  translator’s  ambition  it  should  be,  a sound 
and  comprehensive  system  of  Practical  Surgery.  The  notes  and  text  are  so  intermingled  as  to  render  it  con- 
tinuously readable,  without  presenting  those  abrupt  transitions  which  are  so  disagreeable  in  many  works  simi- 
larly arranged.  The  faults  of  omission,  &c.,  at  which  we  have  hinted  in  our  comments  on  the  first  chapter  of 
our  author's  work,  (viz.  that  on  ‘ Inflammation  ’)  have  been  amply  compensated  by  the  copious  and  excellent 
digest  of  his  translator  and  annotator  who  is  justly  proud  of  availing  himself  of  the  labors  of  our  own  coun- 
trymen in  this  department  of  pathology,  while  he  gives  their  due  meed  of  notice  and  respect  to  the  contributions 
of  our  continental  brethren.  The  references  which  are  given  to  original  works  have  evidently  been  carefully 
collated,  and  will  be  found  of  great  value  to  the  student  and  practitioner  who  may  wish  for  more  copious  in- 
formation on  any  particular  branch  of  Surgery;  and  the  practical  remarks  and  illustrations  with  which  the 
work  abounds,  are  a good  guarantee  of  the  translator’s  ability  to  do  justice  to  his  task,  at  the  same  time  that 
they  prove  that  Mr.  South  has  not  failed  to  avail  himself  industriously  of  the  large  opportunities  which  his  Hos- 
pital appointment  has  affdrded  him.” — The  British  and  Foreign  Medical  Review. 

“ We  will,  therefore,  content  ourselves  for  the  present  with  directing  the  attention  of  the  profession  to  it,  as 
being  the  most  complete  system  of  Surgery  in  any  language,  and  one  that  is  of  equal  utility  as  a practical  guide 
and  as  a work  of  reference.  The  fact  of  its  having  reached  six  editions  in  Germany,  and  its  having  been  trans- 
lated into  seven  languages,.are  more  convincing  proofs  of  its  value  than  anything  that  we  can  say.  Mr.  South 
has  performed  his  task  with  much  judgment,  and  has  certainly  made  a most  useful  addition  to  the  medical  lite- 
rature of  this  country  by  rendering  Chelius’s  work  into  English  The  Lancet. 

“ This  work  has  long  been  the  chief  text-book  on  Surgery  in  the  principal  schools  of  Germany,  and  the  pub- 
lication of  five  editions  of  it  in  the  original  and  of  translations  into  no  less  than  eight  foreign  languages,  show 
the  high  estimation  in  which  it  is  held.  As  a systematic  work  on  Surgery  it  has  merits  of  a high  order.  It  is 
methodical  and  concise— and  on  the  whole  clear  and  accurate.  The  most  necessary  information  is  conveyed 
in  the  shortest  and  simplest  form.  Minor  details  and  fruitless  speculations  are  avoided.  It  is,  in  fact,  essen-  { 
tially  a practical  book.  This  work  was  first  published  nearly  twenty  years  ago.  and  its  solid  and  permanent  j 
reputation  has  no  doubt  led  Mr.  ^outh  to  undertake  the  present  translation  of  the  latest  edition  of  it,  which,  we  ,| 
are  informed,  is  still  passing  through  the  press  in  Germany.  We  should  have  felt  at  a loss  to  select  any  one 
better  qualified  for  the  task  than  the  translator  of  Otto*s  Compendium  of  Human  and  Comparative  Pathological  | 
Anatomy — a surgeon  to  a large  hospital,  whose  industry  and  opportunities  have  enabled  him  to  keep  pace  with  | 
the  improvements  of  his  time.” — The  Medico- Chirurgical  Review. 

“Although  Great  Britain  can  boast  of  some  of  the  most  skilful  surgeons,  both  among  her  past  and  her  present  I 
professors  of  that  branch  of  medical  science,  no  work  professing  to  be  a complete  system  of  Surgery  has  been  | 
published  in  the  British  dominions  since  that  of  Benjamin  Bell,  now  more  than  half  a century  old. 

“This  omission  in  English  medical  literature  is  fully  and  saiisfactorily  supplied  by  the  translation  of  Professor  | 
Chelius’s  System  of  Surgery  by  a gentleman  excellently  fitted  for  the  task,  both  by  his  extensive  reading,  and  | 
the  opportunities  of  practical  experience  which  he  has  enjoyed  for  years  as  surgeon  to  one  of  our  largest  me-  j 
tropolitan  hospitals.  The  fact  ot  Professor  Chelius’s  work  having  been  translated  into  seven  languages  is  suf-  ; 
ficient  proof  of  the  estimation  in  which  it  is  held  by  our  continental  brethren,  and  the  English  edition,  now  in  i 
course  of  publication,  loses  none  of  the  value  of  the  original  from  the  treatment  received  at  the  hands  of  its  I 
translator.  The  notes  and  additions  of  Professor  South  are  numerous,  and  contain  the  opinions  resulting  from  I 
his  vast  experience,  and  from  that  of  his  colleague. 

“ We  are  free  to  confess,  prejudiced  though  perhaps  we  are,  in  favor  of  the  English  practice  of  surgery,  that  j 
®his  work  is  one  of  great  value,  and  one  which  every  practitioner  and  advanced  student  should  possess.” — The  j 

Medical  Times. 


WORKS 


IN 


VARIOUS  DEPARTMENTS 

OF 

MEDICINE  AND  SURGERY, 

PUBLISHED 

BY  LEA  & BLANCHARD. 


AMERICAN  JOURNAL  OF  THE  MEDICAL  SCIENCES.  Edited  by  Isaac  Hays,  M.  D. 
Published  quarterly  at  §5  00  per  annum. 

ANDRAL  ON  THE  BLOOD.  Pathological  Haematology  ; an  Essay  on  the  Blood  in  Dis- 
ease. Translated  by  J.  F.  Meigs  and  Alfred  Stille.  In  one  octavo  volume,  cloth. 

ARNOTT’S  PHYSICS.  The  Elements  of  Physics  in  plain  or  non-technical  language.  A 
New  Edition.  Edited  by  Isaac  Hays,  M.  D.  In  1 vol.  8vo.,  sheep,  with  176  wood-cuts. 

ABERCROMBIE  ON  THE  STOMACH.  Pathological  and  Practical  Researches  on  Dis- 
eases of  the  Stomach,  Intestinal  Canal,  &c.  Fourth  Edition.  In  1 vol.  8vo.,  sheep. 

ABERCROMBIE  ON  THE  BRAIN.  Pathological  and  Practical  Researches  on  the  Dis- 
eases of  the  Brain  and  Spinal  Cord.  A New  Edition.  In  one  octavo  volume,  sheep. 

ALISON'S  PATHOLOGY.  Outlines  of  Pathology  and  Practice  of  Medicine.  In  three 
parts,  containing  Preliminary  Observations,  Inflammatory  and  Febrile  Diseases,  and 
Chronic  or  Non-Febrile  Diseases.  In  one  neat  octavo  volume,  sheep. 

BIRD  ON  URINARY  DEPOSITS.  Urinary  Deposits,  their  Diagnosis,  Pathology  and  The- 
rapeutical Indications.  In  one  neat  octavo  volume,  cloth,  with  numerous  wood-cuts. 

BERZELIUS  ON  THE  KIDNEYS  AND  URINE,  in  1 vol.  8vo.,  cloth. 

BUCKLAND’S  GEOLOGY.  Geology  and  Mineralogy,  with  reference  to  Natural  Theology. 
A Bridgewater  Treatise.  In  two  octavo  volumes,  with  numerous  maps,  plates,  &c. 

BRIDGEWATER  TREATISES.  The  whole  complete  in  7 vols.  8vo.,  containing  Roget’s 
Animal  and  Vegetable  Physiology,  in  2 vols.,  with  many  cuts;  Kirby  on  the  History, 
Habits  and  Instinct  of  Animals,  1 vol.  with  plates  ; Prout  on  Chemistry ; Chalmers  on  the 
Moral  Condition  of  Man ; Whewell  on  Astronomy  ; Bell  on  the  Hand ; Kidd  on  the  Phy- 
sical Condition  of  Man;  and  Buckland’s  Geology,  2 vols.,  with  many  plates  and  maps. 

BARTLETT  ON  FEVERS  OF  U.  S.  The  History,  Diagnosis  and  Treatment  of  Typhus 
and  Typhoid  Fevers,  and  on  Bilious  Remittent  and  Yellow  Fever.  In  L vol.  8vo.,  ex.  cloth. 

BARTLETT’S  PHILOSOPHY  OF  MEDICINE.  Essay  on  the  Philosophy  of  Medical 
Science.  In  two  Parts.  One  neat  octavo  volume,  extra  cloth. 

BRIGHAM  ON  MIND,  &c.  The  Influence  of  Mental  Excitement  and  Mental  Cultivation 
on  Health.  In  one  neat  12mo.  volume,  extra  cloth. 

BILLING’S  PRINCIPLES  OF  MEDICINE.  The  First  Principles  of  Medicine.  From  the 
Fourth  London  Edition.  In  one  octavo  volume,  cloth. 

CHITTY’S  MEDICAL  JURISPRUDENCE.  A Practical  Treatise  on  Medical  Jurispru- 
dence. With  Explanatory  Plates.  In  one  octavo  volume,  sheep. 

CLATER  AND  SKINNER’S  FARRIER.  Every  Man  his  own  Farrier.  Containing,  the 
Causes,  Symptoms,  and  most  approved  Methods  of  Cure  of  the  Diseases  of  Horses. — 
From  the  28th  London  Edition.  Edited  by  Skinner.  In  one  12mo.  volume,  cloth. 

CLATER  AND  YOUATT’S  CATTLE  DOCTOR.  Every  Man  his  own  Cattle  Doctor— 
Containing  the  Diseases  of  Oxen,  Sheep,  Swine,  &c.  Edited  by  Youatt,  and  revised  by 
Skinner.  With  Wood-cuts.  In  one  volume  12mo. 

DURLACHER  ON  CORNS,  BUNIONS,  &c.  A Treatise  on  Corns,  Bunions,  the  Dis- 
eases of  Nails,  and  the  General  Management  of  the  Feet.  In  one  12mo.  volume,  cloth. 

ELLIOTSON’S  MESMERIC  CASES.  In  one  octavo  pamphlet. 

ESQUIROL  ON  INSANITY.  Mental  Maladies,  Considered  in  Relation  to  Medicine,  Hy- 
giene and  Medical  Jurisprudence.  Translated  by  E.  IC.  Hunt,  M.  D.,  &e.  In  1 vol.  8vo. 

GUTHRIE  ON  THE  BLADDER,  &c.  The  Anatomy  of  the  Bladder  and  Urethra,  and 
the  Treatment  of  the  Obstructions  to  which  those  passages  are  liable.  In  I vol.  8vo, 

HARRIS  ON  MAXILLARY  SINUS.  Dissertation  on  the  Diseases  of  the  Maxillary  Sinus. 
In  one  small  octavo  volume,  cloth. 

29 


30 


LEA  & BLANCHARD’S  PUBLICATIONS. 


KIRBY  ON  ANIMALS.  The  History,  Habits  and  Instinct  of  Animals.  A Bridgewater 
Treatise.  In  one  large  volume  8vo.  with  plates. 

HARRISON  ON  THE  NERVES.  An  Essay  towards  a correct  Theory  of  the  Nervous 
System.  In  one  octavo  volume,  sheep. 

LAWRENCE  ON  RUPTURES.  A Treatise  on  Ruptures,  from  the  fifth  London  Edition. 
In  one  octavo  volume,  sheep. 

MAURY’S  DENTAL  SURGERY.  A Treatise  on  the  Dental  Art,  founded  on  Actual  Ex- 
perience. Illustrated  by  241  Lithographic  Figures  and  54  Wood-cuts.  Translated  by 
J.  B.  Savier.  In  one  octavo  volume,  sheep. 

MULLER’S  PHYSIOLOGY.  Elements  of  Physiology.  Translated  by  Wm.  Baly,  M.D., 
and  edited  and  arranged  by  John  Bell,  M.  D.  In  one  large  octavo  volume,  sheep. 

PROUT  ON  THE  STOMACH.  On  the  Nature  and  Treatment  of  Stomach  and  Renal 
Diseases.  In  one  octavo  volume,  sheep,  with  colored  plates. 

POPULAR  MEDICINE,  BY  COATES.  In  one  octavo  volume,  sheep,  with  Wood-cuts. 

PHILIP  ON  INDIGESTION.  A Treatise  on  Protracted  Indigestion.  In  1 vol.  8vo. 

ROGET’S  PHYSIOLOGY.  A Treatise  on  Animal  and  Vegetable  Physiology,  with  over 
400  illustrations  on  Wood.  In  two  octavo  volumes,  cloth.  A Bridgewater  Treatise. 

ROGET’S  OUTLINES  OF  PHYSIOLOGY.  Outlines  of  Physiology  and  Phrenology.  In 
one  large  octavo  volume,  cloth. 

RIGBY’S  MIDWIFERY.  A System  of  Midwifery.  With  Wood-cuts.  In  1 vol.  8vo. 

RICORD  ON  VENEREAL.  A Practical  Treatise  on  Venereal  Diseases ; with  a Thera- 
peutical Summary,  and  a Special  Formulary.  In  I vol.  8vo.,  cloth. 

ROBERTSON  ON  TEETH.  A Practical  Treatise  on  the  Human  Teeth,  with  plates.  One. 
small  volume  octavo,  cloth. 

TRAILL’S  MEDICAL  JURISPRUDENCE.  Outlines  of  a Course  of  Lectures  on  Medi- 
cal Jurisprudence.  Revised,  with  numerous  notes.  In  one  octavo  volume,  cloth. 

THOMSON’S  SICK  ROOM.  Domestic  Management  of  the  Sick  Room,  Necessary  in  Aid 
of  Medical  Treatment,  for  the  Cure  of  Diseases.  Edited  by  R.  E.  Griffith,  M.  D.  In  one 
large  royal  12mo.  volume,  extra  cloth,  with  Wood-cuts. 

WALSHE  ON  THE  LUNGS.  Physical  Diagnosis  of  the  Diseases  of  the  Lungs.  In 
one  neat  12mo.  volume,  extra  cloth. 

YOUATT  ON  THE  HORSE.  The  Horse:  containing  a full  account  of  the  Diseases  of 
the  Horse,  with  their  mode  of  Treatment;  his  Anatomy,  and  the  usual  Operations  per- 
formed on  him;  his  Breeding,  Breaking,  and  Management;  and  Hints  on  his  Sound- 
ness, and  Purchase  and  Sale.  Together  with  a General  History  of  the  Horse  ; a Dis- 
sertation on  the  American  Trotting  Horse,  how  trained  and  jockeyed,  an  account  of  his 
remarkable  performances;  and  an  Essay  on  the  Ass  and  the  Mule.  By  J.  S.  Skinner, 
Assistant  Postmaster  General,  and  Editor  of  the  Turf  Register.  In  one  volume,  octavo, 
with  numerous  Cuts. 


jnEDICJlli  WORKS,  at  Press  and  Preparing. 


A MANUAL  OF  MATERIA  MEDICA  AND 
Therapeutics.  By  J.  Forbes  Royle,  M.  D.,  &c. 
Edited  by  J.  Carson,  M.  D.,  &c.  In  1 vol.  8vo., 
numerous  wood-cuts,  ( nearly  ready). 

TODD  & BOWMAN’S  PHYSIOLOGICAL  ANA- 
tomy  and  Physiology  ofMan.  Many  wood-cuts, 
( publishing  in  the  Medical  News  and  Library ). 

A TREATISE  ON  OPHTHALMIC  MEDICINE 
and  Surgery.  By  T.  Wharton  Jones.  In  lvol. 
beautifully  illustrated. 

PRINCIPLES  OF  GENERAL  AND  COMPA- 
rative  Physiology.  By  Wm.  B.  Carpenter, 
M.  D.,&c.  From  a new  London  edition,  with 
numerous  improvements  and  additions.  In  1 
vol.  large  8vo.,  many  steel  plates. 

A TREATISE  ON  ANIMAL  PHYSIOLOGY, 
with  very  numerous  illustrations.  By  Wm.  B. 
Carpenter. — To  be  followed  by  his  other  works 
on  Natural  Science. 

A NEW  AMERICAN  FORMULARY.  By  J. 
Carson,  M.  D.,  &c.  In  one  volume,  (preparing). 

A SYSTEM  OF  SURGERY.  By  J.  M. Chelius. 
Translated  by  South,  and  Edited  by  Norris. — 
Publishing  in  numbers  at  50  cents  each.  To 
be  complete  in  three  octavo  volumes. 

HORNER’S  AMERICAN  DISSECTOR,  in  one 
large  12mo.  vol.,  with  many  cuts,  (nearly  ready.) 


AN  ANATOMICAL  DESCRIPTION  OF  THE 
Diseases  of  the  Organs  of  Circulation  and  Re- 
spiration. By  C.  E.  Hasse.  Translated  and 
Edited  by  W.  E.  Swaine,  M.  D.,  &c.  In  1 vol. 
8vo.,  (nearly  ready). 

A TREATISE  ON  AURAL  SURGERY.  In  1 
vol.  8vo.,  many  illustrations. 

A COMPLETE  MEDICAL  BOTANY,  especially 
adapted  to  the  United  States.  By  R.  E.  Grif- 
fith, M.  D.  In  1 vol.  large  8vo.,  with  many 
illustrations. 

LECTURES  ILLUSTRATIVE  OF  VARIOUS 
Subjects  in  Pathology  and  Surgery.  By  Sir  B. 
Brodie — completing  his  works. 

CALORIC,  its  Mechanical,  Chemical,  and  Vital 
Agencies  in  the  Phenomena  of  Nature.  By  S. 
L.  Metcalfe,  M.  D.,  &c.  In  1 large  8vo.  vol. 

GOLDING  BIRD’S  ELEMENTS  OF  NATU- 
RAL PHILOSOPHY.  With  numerous  wood- 
cuts. 

VOGEL’S  PATHOLOGICAL  ANATOMY.— 
Translated  and  Edited  by  G.  Day,  M.  D.,  &c. 
In  1 vol.  large  8vo.,  many  plates. 

BURROWS  ON  CEREBRAL  CIRCULATION, 
with  plates. 

Together  with  other  JVew  Works. 


LEA  & BLANCHARD’S  PUBLICATIONS. 


31 


(See  Page  33.) 

THE  MEDICO-CHIRURGICAL  REVIEW, 

EDINBURGH  MEDICAL  AND  SURGICAL  JOURNAL, 

AND  NUMEROUS  OTHERS. 

WHILE  FROM  FRANCE 

THE  GAZETTE  MEDIC  ALE  DE  PARIS— L’EXPERIENCE— REVUE  MEDIC  ALE 
—JOURNAL  DE  MEDECINE— JOURNAL  DES  CONNAISSANCES 
MEDICO-CHIRURGICALES, 

AND  VARIOUS  OTHERS,  WITH  THE 

ZEITSCHRIFT  FUR  DIE  GESAMMTE  MEDICIN, 

WITH  SEVERAL  OTHERS  FROM  GERMANY , 

AND  THE  BIBLIOTHEK  FOR  LH3GER,  OF  DENMARK, 

TOGETHER  WITH 

Alii*  THE  AMERICAST  JOURCTAX.S, 

ARE  PUT  IN  REQUISITION. 

It  will  thus  be  seen  that  the  material  for  a full  Summary  of  all 

NEW  MATTERS  AND  IMPORTANT  DISCOVERIES 

is  full  and  ample,  while  the  exertions  of  the  Editor  and  the  time  of  publication  insure  a fulness 
and  newness  to  this  department. 

ALL  THE  LATE  AND  IMPORTANT 

AMERICAN  INTELLIGENCE, 

is  fully  recorded— while 

THE  MOATMLY  MEWS 

furnishes  the  lighter  and  floating  information,  and  embraces  important  Books  for 

THE  LIBRARY  DEPARTMENT. 


Among  those  works  already  published  in  the  Monthly  Library  and  News,  may  be  mentioned 

WATSON’S  LECTURES  ON  THE  PRACTICE  OP  PHYSIC, 

AS  ALSO 

BRODIE’S  LECTURES  ON  SURGERY, 

CONCLUDED  IN  MARCH  OF  THIS  YEAR,  (1846). 

The  work  for  the  year  1S46  is  a new  one, 

TODD  & BOWMAN’S 

PHYSIOLOGICAL  ANATOMY  & PHYSIOLOGY  OF  MAN, 

NOW  PUBLISHING  IN  ENGLAND. 

This  work  has  already  earned  for  its  authors  a high  reputation  in  Europe  and  this 
country.  It  will  be  reproduced  entire,  with  all  the  numerous  and  beautiful  wood-cuts. 
Each  Work  in  the  Library  is  regularly  paged  so  as  to  be  bound  separately. 

THE  TERMS  ARE 

For  the  Medical  Journal  and  the  Medical  News,  if  paid  for  by 
the  first  of  February  of  each  Year,  and  the  amount  remitted 
free  of  cost  to  the  Publishers,  -----  Five  Dollars. 

For  the  Journal  only,  when  ordered  without  funds,  or  paid  for 

after  the  first  of  February  of  each  year,  - - - Five  Dollars. 

For  the  Medical  News  only,  to  be  paid  for  always  in  advance, 

and  free  of  postage,  -------  One  Dollar. 

In  no  case  can  the  News  be  sent  without  pay  in  advance.  =#§ 


32  TWO  MEDICAL  PERIODICALS  FOR  FIVE  DOLLARS  A YEAR. 

AMERICAN  JOURNAL  OF  THE  MEDICAL  SCIENCES, 

Edited  by  ISAAC  HAYS,  M.  D. 

SURGEON  TO  WILLS’  HOSPITAL,  ETC. 

Published  Quarterly  on  the  first  of  January,  April,  July  and  October  ; each  Number  having  at  least 
264  large  and  closely  printed  pages. 

AVHEN  NECESSARY,  CASES  ARE 

Fully  Illustrated  with  LITHOGRAPHIC  PLATES  and  WOOD-CUTS. 

ALSO, 

&()e  JlteMcal  Stfevus  a nb  Cibrarg, 

Of  32  Large  Pages,  Published  Monthly,  is  given  Gratis  to  Subscribers 

to  The  Journal  who  pay,  by  the  first  of  February  of  each  year,  Five  Dollars  free  of  expense  to  the 

Publishers. 

Under  the  new  law  the  postage  on  the  Journal  is  reduced  to  about  13|  cents  per  number,  while 
the  News  and  Library  is  sent  through  the  mail  as  a Newspaper. 

Persons  wishing  to  subscribe,  to  commence  with  the  January  number  for  1847,  should  advise  the 
publishers  at  once,  as  the  whole  quantity  for  the  present  and  two  past  years  was  taken  up  early 
in  the  year. 

The  publishers  do  not  deem  it  necessary  to  refer  to  the  past  course  of  the  Journal.  It  is  suffi- 
cient that  for  the  last  TWENTY-SEVEN  YEARS  it  has  received  the  approbation  of  the  profession 
at  home  and  abroad  ; but  they  would  call  attention  to  the  extended  and  liberal  arrangement  exist- 
ing and  to  be  pursued  that  shall  embody  the  latest  intelligence  from  all  quarters. 

ITS  PAGES  WILL  BE  DEVOTED  FIRST  TO 

ORIGINAL  COMMUNICATIONS 

FROM  ALL  SECTIONS  OF  THE  UNION,  WITH 

REVIEWS  OF  ALL  NEW  WORKS 

OF  INTEREST,  AND 

i D ! L D © © IR  /&  P U Q © A L ^©TB©Eig 

While  its  QUARTERLY  SUMMARY  will  embrace  a full  and  extended 

RETROSPECT  AND  ABSTRACT 

FROM  THE  VARIOUS 

FOREIGN  AND  DOMESTIC  JOURNALS. 

With  reference  to  this  department,  the  arrangements  of  the  publishers  are  very  extensive  and  em- 
brace for  the  gleanings  of  the  editor  the  various  Journals  from 

GREAT  BRITAIN,  FRANCE,  GERMANY, 

DENMARK,  ITALY, 

.7.V/J  OTHER  SECTIONS  OF  THE  WORLD. 

INCLUDING  AS  PROMINENT  AMONG  THE  ENGLISH, 

BRAITHWAITE’S  RETROSPECT, 

RANKING’S  HALF-YEARLY  ABSTRACT, 

THE  LONDON  MEDICAL  TIMES, 

THE  LONDON  MEDICAL  GAZETTE, 

FORBES’  BRITISH  AND  FOREIGN  QUARTERLY. 


(Continued  on  Page  31.) 


frCr  This  paper  may  be  delivered  to  any  physician  if  declined  by  the  person  to  whom  it  is  ad- 
dressed, or  if  they  have  removed — and  Postmasters  and  others  will  particularly  oblige  the  publish- 
ers by  furnishing  a list  of  the  Physicians  and  Lawyers  of  their  county  or  neighborhood.  In  addition 
to  the  business  it  may  bring  to  the  office,  a copy  of  “ The  Complete  Florist,”  or  such  other  volume, 
will  be  sent  by  mail  gratis  for  any  ten  or  more  names  furnished  free  of  cost. 

Philadelphia,  July,  1846. 


• v\» 


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